The Tet Offensive: Intelligence Failure in War

Introduction

On 31 January 1968, during the Tet holiday, communist forces simultaneously attacked urban areas, military installations, and government facilities throughout South Vietnam. By the time the offensive’s intensity began to wane on 13 February, 1100 Americans had been killed in action, and members of the Johnson administration and the American public had been stunned by the fury of the Tet attacks. Following the offensive, the official U.S. government investigation into the circumstances surrounding the Tet attacks concluded that, although warning had . . . been provided, the intensity, coordination, and timing of the enemy attack were not fully anticipated.¹ U.S. and South Vietnamese officers and intelligence analysts failed to anticipate the nature of the Tet offensive. This failure not only contributed to the initial military gains enjoyed by the communists but also increased the shock produced by the attack. Ultimately, it was the surprise, not the short-term military advantages, that reduced the willingness of the American public and political elite to continue to prosecute the war in Vietnam.²

The Tet offensive was the decisive battle of the Vietnam War because of its profound impact on American attitudes about involvement in Southeast Asia. In the aftermath of Tet, many Americans became disillusioned with the Johnson administration’s conduct of the war. To the American public and even to members of the administration, the offensive demonstrated that U.S. intervention in the ground war had produced a negligible effect on the will and capability of the Vietcong and North Vietnamese to continue in their struggle to unite Vietnam. The Tet offensive seemed to indicate to most observers that the three years of big-unit war that followed the deployment of U.S. ground forces in 1965 had produced only a steady stream of casualties on all sides. On the battlefield, Tet marked the turning point between U.S. escalation and withdrawal from the war.

In the realm of domestic politics, the consequences of the offensive were also profound. Tet discredited the Johnson administration, reinforcing the president’s decision not to run for reelection. For many Americans, Tet enhanced the credibility gap between the electorate and government officials as battlefield developments apparently contradicted the claims of progress in the war made by the Johnson administration and the military. The offensive turned disengagement from the struggle in Vietnam into the American political priority for the next five years. Over the longer term, Tet marked the beginning of what Ronald Reagan called the Vietnam syndrome: a period of public disillusionment with military intervention, defense spending, and an active anticommunist approach to foreign affairs. In a sense, the Tet offensive quelled the crusading spirit that characterized America’s postwar rush to intervene in conflicts in the Third World.

Given the political impact of the Tet attacks, it would be logical to assume that the offensive dealt a devastating military setback to U.S. forces and their South Vietnamese allies. Dire consequences usually follow a disastrous defeat. Ironically, the allies defeated the communists decisively during Tet. From the communist perspective, the offensive was a gamble, even a desperate gamble, taken to offset the overwhelming resources, mobility, firepower, technological sophistication, and professionalism of their opponent. The North Vietnamese and Vietcong hoped that the attacks would foster a revolt of the southern population against the government, thereby adding tens of thousands of combatants to the communist side. When the offensive failed to spark this insurrection, communist commanders lacked the resources needed to attain their ambitious objectives, and the allies defeated their widely scattered forces piecemeal. Even though the Tet attacks failed to unfold as planned, the offensive eventually produced the outcome desired by the communists.

The communists intended the surprise inflicted against the allies during Tet. They adopted a sophisticated strategy of deception, misleading their opponents about their intentions in a quest to eliminate or reduce the effectiveness of responses to the offensive. In wartime, the active or passive effort to mislead, misinform, or confuse an opponent about one’s capabilities or intentions can take several forms. A nation contemplating an attack can try to make its adversary locate its forces in the wrong place. In such instances, deceptive operations embody all the signs of a real assault, to cause an opponent to believe that the pretended hostile activities are genuine. The Japanese attack on the Aleutians on 3 June 1942, an effort to lure the U.S. Navy away from the Japanese forces that would conduct the planned amphibious landings on Midway, is an example of this type of operation. Deception during war also can be used to force an opponent to violate the principle of economy of force. Such cases involve the attempt to cause the adversary to squander resources on nonexistent targets or in unimportant directions. During the Battle of Britain, for example, the British succeeded in channeling German air attacks away from actual facilities by constructing fake installations and by interfering with the Luftwaffe’s electronic navigational aids. Cover, another type of deception, is intended to lull an opponent into a false sense of security so that one can seize the element of surprise. Here deception centers on the effort to disguise preparations for attack by convincing the opponent that genuinely hostile activities are harmless. Before Operation Barbarossa, the German invasion of the Soviet Union, the Nazis maintained normal diplomatic and economic relations with the Soviets in an ultimately successful effort to hide their preparations for invasion. Before Tet, the communists used a mix of active and passive deceptive strategies to mislead the allies about the location of the offensive and to hide preparations for the coming attacks. This strategy was insufficient to secure military victory for the communists, but it did help to obtain the element of surprise.³

If the communists failed to win the Tet offensive, what then accounts for its effect on American perceptions of the war in Vietnam? Ultimately, the shock it produced was the catalyst that led to the reevaluation of U.S. policy. The Tet attacks failed on the battlefield, but U.S. forces did not anticipate fully the scope, intensity, targets, and timing of the offensive. The allies suffered a failure of intelligence during Tet, a failure that set the stage for changes in U.S. strategy.

Why were the United States and its allies surprised by the Tet attacks? Intelligence analysts, soldiers, and political officials are generally surprised by their opponent’s initiatives if they fail to accomplish four tasks, sometimes referred to as the intelligence cycle: collection of information, analysis, response, and dissemination of warning. The first task is the collection of accurate information about the opponent’s intentions and capabilities. There are, of course, a variety of ways to collect information about potential adversaries, from simply reading the foreign press to using advanced technology to monitor the opponent’s communications. Yet collection can be arduous because governments bent on surprising their opponents strive to prevent accurate information from reaching their victim. Even though the notion is tautological, surprise can occur because the victim lacks information about the opponent. In any event, one should not dismiss this most parsimonious explanation for a failure of intelligence without first demonstrating that information that could have warned the victim of what was about to unfold was available.⁴

It could be argued that, on balance, U.S. intelligence organizations enjoyed several advantages simply because they were already at war. Certain methods of collecting information obviously were not available; U.S. diplomats and journalists could not wander Hanoi listening for the latest rumor about the regime’s intentions. But during war, events on the battlefield can produce an intimate, albeit sometimes painful, awareness of the opponent’s idiosyncrasies and standard procedures. Other sources of information generally unavailable in peacetime—reconnaissance overflights, captured documents, and prisoner interrogations—also become available during hostilities. Although it was formidable, the task of collecting information before Tet was not insurmountable from the U.S. perspective.

The second task, the analysis of evidence of enemy intentions and capabilities, is crucial, given the assumption that all information is inherently ambiguous. Current developments in widely scattered regions must be combined into a meaningful pattern. Past events must be linked to reports of future plans. Analysts also must differentiate between signals (accurate information about the enemy) and noise (inaccurate or irrelevant information) in attempting to predict the opponent’s moves. In devising estimates, however, analysts are subjected to a variety of pressures. For example, the cry wolf syndrome, a set of consequences that flow from the fact that a price must be paid for the sounding of false alarms, can complicate the analytical process. For analysts, this syndrome creates an incentive to make deliberately vague estimates to avoid the professional censure and personal ridicule involved in offering clear, but inaccurate, analyses. In effect, the intellectual challenges involved in predicting the opponent’s behavior can be daunting.⁵

The third task, the decision to respond to a warning issued in the analytical stage, is usually the responsibility of policy makers. To be effective, the response chosen must be attuned to the developing threat. In selecting an effective response and ordering its implementation, policy makers also have to overcome obstacles. The cry wolf syndrome can again exert an influence. Repeated false alarms can desensitize policy makers to warnings, causing them to fail to respond to an accurate warning. Moreover, because the United States was already at war, the false alarm rate could easily have soared. Analysts could be expected to see the greatest peril in the most mundane events, forcing policy makers to differentiate between the gravity of repeated warnings. Another obstacle is concern about miscalculated escalation; initiatives taken to lessen the impact of an attack could be perceived as threatening by a potential adversary, provoking the opponent to launch a preemptive attack in a crisis that otherwise would have been solved peacefully. Before the outbreak of the October War, for example, the Israelis delayed ordering a general mobilization because of their concerns about miscalculated escalation. Similar concerns also tempered the British response to indications that Argentina was planning to invade the Falkland Islands in 1982. During war, however, concerns about miscalculated escalation should not preoccupy policy makers; it is difficult to imagine how preparations to meet an attack could further exacerbate a conflict once hostilities have started. Ironically, the response of the Johnson administration to warnings of impending attack was shaped by concerns about miscalculated escalation.⁶

The fourth stage of the intelligence cycle is the dissemination of the order to respond to individuals, in this case field commanders. This is no small task: warning is likely to be ignored if the alert is not convincing or if the actions ordered do not seem relevant to the situation confronting the local commander. Moreover, because hundreds, even thousands, of small-unit commanders need accurate and appropriate information, the dissemination of warning throughout a command, even aided by modern communications, is a huge enterprise. Alerting a large army is like stopping a large truck. The driver can spot the danger ahead and even apply pressure to the brakes, but the time and distance needed to avoid the danger may not be available. Similarly, analysts and policy makers may recognize and warn of an impending threat, but the time needed to reorient the army to meet an attack may not exist. In a sense, analysts and policy makers face a point of no return; after a certain time, alerts issued in response to indications of attack produce diminishing results. Even though the point of no return is scenario-specific, the greater the number of individuals who need to be warned about an impending initiative, the earlier the point of no return arrives before an attack. Because the U.S. leadership had to advise not only their own army but several allied contingents (the South Vietnamese and Koreans) prior to Tet, the need to issue an alert before the point of no return was particularly challenging.

One final observation should be made about the completion of each stage of the intelligence cycle. Those attempting to anticipate an opponent’s actions face an inherent disadvantage: a time lag exists between the moment an opponent undertakes preparations for an initiative and the point when these preparations can be first detected. Time elapses before preparations for an attack generate enough signals to stand out against the noise produced by normal levels of activity or efforts at deception. In other words, opponents obtain a head start over victims’ attempts to predict their actions, and this inherent disadvantage is further exacerbated by the relatively slow process of collecting and analyzing information and selecting and disseminating a response. Intelligence organizations and policy makers are in a race to catch up with their opponents. They fail to win the race if they are unable to anticipate their opponent’s initiatives before crossing the point of no return, the point when it becomes impossible to avoid the operational consequences of surprise.⁷

The intelligence cycle must be completed to avoid surprise; thus, it can be used as a tool to identify an intelligence failure. Each stage of the cycle must reflect an accurate and timely analysis of six empirical issues: (1) identity of the adversary; (2) probability of attack; (3) type of action involved; (4) location of the attack; (5) timing of the action; and (6) motivation behind the initiative. If these issues are not adequately addressed at each stage of the cycle, then the probability of a surprise increases dramatically. In a sense, then, these problems can be used to identify specific shortcomings at each stage of the intelligence cycle.⁸

Because they were already in a war, the Americans’ empirical intelligence problems were relatively modest. After hostilities have commenced, the likelihood of continued attack can be assumed to be high. Because the communists lacked airborne, naval, amphibious, aircraft, and nuclear capabilities, U.S. analysts could assume that any offensive would take the form of infantry and artillery attacks. The identity of the opponent to be faced was also clear; the North Vietnamese and Vietcong had already been identified as the enemy. Paradoxically, intelligence analysts would have been better served by contravening conventional wisdom and entertaining the possibility that new adversaries (the South Vietnamese army and civilians) would join the communists during Tet by staging a revolt against the government. In any event, to avoid surprise, the allies needed to develop an accurate and timely response to only four questions: who was the opponent, and where, when, and why (in the sense of avoiding some disaster or to take advantage of some opportunity) would their opponent attack.

Because the problem of averting surprise attack in wartime is at least theoretically simpler than that of averting surprise at the outbreak of hostilities, the Tet offensive is a critical test of an explanation of intelligence failure. Stated simply, since U.S. forces were already at war with the North Vietnamese and the Vietcong, they confronted a situation in which a successful surprise attack was least likely, a situation in which the probability of some hostile action by the opponent could be taken as given. Still, they were surprised. An analysis of their intelligence activities in terms of the intelligence cycle should indicate why nations often fall victim to surprise attack. An inaccurate analysis of information or a failure to predict the location of an attack does not, however, completely explain the surprise during Tet. To address this kind of event, scholars have used theories drawn from several levels of analysis. These theories identify variables that often determine whether nations attempting to avoid surprise attack are successful: situational factors peculiar to the production of intelligence estimates, bureaucratic imperatives that shape the production of intelligence estimates, and the way individuals interpret information.

The situational level of analysis explores the way the pressures, concerns, and impediments inherent in the enterprise of intelligence analysis can determine whether accurate estimates are produced. The cry wolf syndrome, already mentioned, is just one of these factors. Analysts can also be affected by the ultra syndrome, a tendency to become overly reliant on sources with a reputation for providing accurate and timely information. Additionally, analysts can be affected by the intelligence-to-please syndrome, a tendency to produce intelligence estimates that support current policy even though information indicates that policy is failing. This syndrome usually stems from difficulties encountered in maintaining a division of labor between intelligence analysis and policy formulation. In theory, intelligence estimates should be totally divorced from policy formulation. In practice, however, analysts must be aware of current policy initiatives if their intelligence estimates are to have any relevance. Since pleasing estimates are often rewarded, intelligence analysts are motivated to produce estimates that support policy makers’ preferences. Sometimes the intelligence-to-please syndrome is a result of outright pressure from intelligence consumers for estimates that support existing preferences. Allegations exist, for example, that civilian and military intelligence analysts were pressured by senior officers and administration officials to provide evidence that U.S. policies toward Vietnam were succeeding.⁹

Theories at the bureaucratic level explain how the behavior and perceptions of individuals are influenced by their organizational affiliation. Such explanations are based on the notion that individuals tend to modify their objectives, attitudes, and conduct so that they match the missions, procedures, and goals of their organization. Depending on the particular bureaucracy, the qualities valued by an organization may not be useful in helping to predict the future moves of an opponent. Additionally, bureaucracy itself—hierarchy, specialization, centralization, routine, secrecy, and especially compartmentalization—can all work to impede analysis. Theories on this level also explore the severe disruption bureaucratic rivalry can bring to the production of intelligence estimates.¹⁰

In this book, situational and bureaucratic explanations for failures of intelligence are treated as second-order, not primary, explanations for the surprise suffered during Tet. Instead, my analysis focuses on the theory of unmotivated biases, a cognitive explanation of decision making that posits that individuals do not follow a rational process in making decisions.¹¹ The theory of unmotivated biases suggests that a belief system acts to insulate the decision maker from information that contradicts the system. When used in the context of the theory of unmotivated biases, the term belief system denotes the ideas held by individuals concerning the nature of the world and the motives of other actors. Individuals usually form these beliefs by drawing on either stereotyped interpretations of dramatic historical events, especially wars and revolutions, or powerful personal experiences. When individuals make a decision, they attempt to place ongoing events in the context of preexisting beliefs, beliefs that often take the form of historical analogies. This phenomenon tends to shape decision making in three important respects. First, belief systems filter the individual’s receptivity to information. Decision makers pay attention to information that confirms their beliefs and dismiss information that disconfirms them. If a particular belief system is used to interpret a given situation, it continues to filter new information in a manner that confirms the applicability of the belief system to developing events. Second, decision makers choose before sufficient information has been collected or evaluated. As a result of this premature cognitive closure, according to Richard Ned Lebow, policy-makers will proceed a long way down a blind alley before realizing that something is wrong.¹² In other words, individuals tend to make a decision when they possess information that confirms their preexisting beliefs, even though this information may fail to describe adequately the present situation. Finally, belief systems can desensitize individuals to the need to make value trade-offs. Because of a lack of sensitivity to information that calls into question their preexisting beliefs, decision makers are likely to assert that a preferred option will simultaneously support all their goals.¹³

In this book, the theory of unmotivated biases is used to explain how analysts and policy makers addressed the empirical questions confronting them during each phase of the intelligence cycle surrounding the Tet offensive. I examine U.S. officials’ beliefs about the situation in Vietnam and the information they possessed. Was the U.S. response to unfolding events appropriate to the information available, or does it reflect U.S. policy makers’ belief systems? Part I addresses this question by examining the Tet offensive from the communist perspective. Chapter 1 describes the bruising strategic debate that preoccupied the communist leadership following U.S. intervention in the ground war. I advance a proposition that has largely been overlooked in the literature on Vietnam: U.S. intervention was a significant obstacle in the path of the communist effort to unite Vietnam. The communists launched Tet not only to take advantage of weaknesses in the opposing alliance but also to break a military stalemate, a stalemate that was slowly eliminating their ability to use offensive military action to influence the course of the war. Chapter 2 examines another issue largely overlooked in the literature on the war, the communists’ strategy of deception. By clarifying the communist motivations and preparations for launching the surprise offensive, this section illustrates the problems confronting the allies as they attempted to predict future battlefield developments between June 1967 and January 1968.

In Part II, the analysis moves to the Americans’ beliefs about the status of the allied and communist war efforts and communist behavior during truces, and to the analogies U.S. commanders used to explain and predict communist initiatives. Chapter 3 traces the origin of these beliefs and describes the expectations they created among the U.S. leadership about future communist activity on the battlefield. Chapters 4 and 5 describe the information available to U.S. officials and officers before the Tet attacks and the way preexisting beliefs guided their interpretation of indications that the communists were about to launch a major offensive. Chapter 6 shows the U.S. military and intelligence reaction to the Tet attacks, including the lingering influence of beliefs held before the offensive on the way some individuals interpreted enemy intentions. As we also see in Chapter 6, some analysts learned from the surprise suffered during Tet and successfully predicted that the communists would renew their offensive during February and May 1968.

In the Conclusion, the question that frames this analysis—why were the Americans surprised by the Tet attacks?—is answered. The communists’ deceptive strategy is evaluated, thereby tracing the parameters of the problem U.S. intelligence had to overcome to avoid surprise. At what point in the intelligence cycle Americans failed is identified. Relying on the theory of unmotivated biases, the conclusion explains why the Americans did not develop an accurate response to the empirical issues that underlie the intelligence cycle.

Given its theoretical approach and structure, this book is intended not only to contribute to the history of the Vietnam War but to follow in a tradition of inquiry that has long fascinated political scientists, the study of intelligence failure. Starting with the Roberts commission, which convened on 22 December 1941, the effort to understand and prevent a repetition of the surprise attack suffered at Pearl Harbor has attracted the attention of many scholars. These efforts produced dozens of analyses, culminating in a major study of intelligence failure, Roberta Wohlstetter’s Pearl Harbor Warning and Decision. Wohlstetter’s work set the tone for future studies in identifying three factors in the failure of intelligence: the signal-to-noise ratio, or the strength of sources of accurate information relative to the strength of confusing or distracting background stimuli; the expectations of the observers; and the rewards and disadvantages of recognizing and correctly analyzing signals. Richard Betts, in his more reincent Surprise Attack, has added to this list of factors the difficulty inherent in communicating warnings throughout a chain of command and the consequent slowing or even prevention of an effective response.¹⁴ Complimenting Wohlstetter’s work is Allen Whiting’s classic China Crosses the Yalu, an examination of the motivations, perceptions, and policy deliberations that shaped the Chinese decision to intervene in the Korean War. Whiting’s analysis addresses the topic of intelligence failure, not from the victim’s perspective, but from that of the side that intends to inflict a surprise. Similarly, Barton Whaley and Michael Handel have described the impact of an opponent’s deceptive strategies on the likelihood of intelligence failure.¹⁵

The study of the failure of intelligence suffered by the United States during the Tet offensive can contribute to an understanding of intelligence failure in international relations. In examining the Tet offensive from both the allied and communist perspective, an obvious yet often unexpected fact that sometimes contributes to failures of intelligence is revealed. To avoid surprise, it is often necessary to anticipate the opponent’s mistakes. Nations sometimes surprise their opponents by reaching for overly ambitious objectives. Although they often fail to gain these objectives, they may surprise their opponents in the attempt to attain them. But the effort to anticipate the opponent’s mistakes, confronts analysts with an extremely difficult problem. Not only must they recognize that the opponent is about to launch an initiative based on faulty information or inaccurate estimates; they must also convince policy makers that the opponent is about to undertake some enterprise that is likely to fail. Instead of responding to indications that the opponent is about to undertake an irrational endeavor, the victim of the looming surprise becomes preoccupied with concerns about enemy deception.

Before Tet, the possibility that the communists miscalculated became more than just hypothetical. Joseph Hovey, an analyst with the Central Intelligence Agency, developed an accurate prediction of the Tet offensive months before the attacks unfolded. His analysis was circulated among senior officers and officials in the Johnson administration, including the president. Even though his warning of an offensive of unprecedented scope was generally viewed as well reasoned and provocative, all his observations, save one, were dismissed. Hovey’s explanation of the communists’ motivation for launching the offensive—that they were in dire straits—was viewed as the key analytical element in his estimate. As strange as it appears, his prediction of a major offensive was interpreted as a welcome development, a sign that U.S. policies in Vietnam were succeeding. It would, then, be wrong to underestimate the gravity of the intelligence task faced by the allies as they attempted to anticipate their opponents’ next move on the battlefield. Indeed, even under ideal conditions, intelligence analysts face an intellectual problem of enormous difficulty. Immersed in day-to-day events, overwhelmed by administrative details, and bombarded with erroneous and trivial information, they must retain the analytical detachment, the ability to see the big picture, needed to recognize unexpected patterns and trends. Worse still, hindsight makes their errors of omission and commission all too painfully obvious and obscures the small analytical triumphs that can minimize failures of intelligence. It would also be wrong not to state at the outset that U.S. intelligence agents missed avoiding the operational consequences of surprise by just a few hours. They almost got it right. Given these circumstances, little effort is made to apportion blame among individuals and organizations for the surprise suffered during Tet. Those looking for villains in this book will be disappointed.

¹U.S. Congress, House Select Committee on Intelligence, U.S. Intelligence Agencies and Activities: Risks and Control of Foreign Intelligence, 94th Cong., 1st sess. 1975, pt. 5, app. 4, 1995.

²Headquarters, United States Military Assistance Command, Vietnam, Command History 1968 (San Francisco, 1969), 1: 129; and George C. Herring, America’s Longest War: The United States and Vietnam, 1950–1975 (New York, 1979), p. 188.

³Charles Cruickshank, Deception in World War II (Oxford, 1979), p. xi; Michael Handel, Military Deception in Peace and War (Jerusalem, 1985), pp. 9–11; Gordon W. Prange, Miracle at Midway (New York, 1982), p. 116; Samuel Eliot Morison, History of United States Naval Operations in World War II, vol. 4. Coral Sea, Midway and Submarine Actions (Boston, 1949), p. 77; and Barton Whaley, Codeword BARBAROSSA (Cambridge, Mass., 1973).

⁴Michael Handel, The Politics of Intelligence Intelligence and National Security (October 1987), 5; Walter Laqueur, 4 World of Secrets (New York, 1985), pp. 20–37; and Ariel Levite, Intelligence and Strategic Surprises (New York, 1987), pp. 8–9. It should be noted that the specification of intelligence requirements, the decision to attempt to collect certain kinds of information, is usually included in discussions of the intelligence cycle. The listing of intelligence requirements did not, however, play a part in the surprise suffered by the allies during Tet; battlefield operations often generated more captured documents and prisoners than intelligence organizations could handle.

⁵Roberta Wohlstetter, Pearl Harbor: Warning and Decision (Stanford, Calif., 1962), pp. 1–3; Ephraim Kam, Surprise Attack: The Victim’s Perspective (Cambridge, Mass., 1989), pp. 186–187; and Levite, Intelligence and Strategic Surprises, pp. 17–18.

⁶Kam, Surprise Attack, 187–189; Richard Betts, Surprise Attack (Washington, D.C., 1982), p. 145; Janice Gross Stein, Calculation, Miscalculation, and Conventional Deterrence II: The View from Jerusalem, in Psychology and Deterrence, ed. Robert Jervis, Richard Ned Lebow, and Janice Gross Stein (Baltimore, 1985), p. 62; Michael Handel, Perception, Deception and Surprise: The Case of the Yom Kippur War (Jerusalem, 1976), p. 41; and Richard Ned Lebow, Miscalculation in the South Atlantic: The Origins of the Falklands War, in Psychology and Deterrence, ed. Jervis et al. pp. 100–102.

⁷Levite, Intelligence and Strategic Surprises, pp. 13–15; Michael Handel, Intelligence and the Problem of Strategic Surprise, Journal of Strategic Studies 7 (September 1984), 237–241; and Edwin T. Layton, Roger Pineau, and John Costello, And I Was There: Pearl Harbor and Midway—Breaking the Secrets (New York, 1985), p. 22.

⁸Alexander George, Warning and Response: Theory and Practice, in International Violence: Terrorism, Surprise, and Control, ed. Yair Evon (Jerusalem, 1979), pp. 12–24; Levite, Intelligence and Strategic Surprises, pp. 2–3; and Kam, Surprise Attack, p. 8.

⁹Kam, Surprise Attack, p. 42; Levite, Intelligence and Strategic Surprises, pp. 16–17; Laqueur, World of Secrets, pp. 102–109; Richard K. Betts, Intelligence for Policymaking, Washington Quarterly 3 (Summer 1980), 119; T. L. Cubbage II, Westmoreland vs. CBS: Was Intelligence Corrupted by Policy Demands? (Paper presented at the Intelligence and Military Operations Conference, U.S. Army War College, May 1987); and Samuel Adams, Vietnam Cover-up: Playing with Numbers, Harper’s, May 1975.

¹⁰Graham T. Allison, Essence of Decision: Explaining the Cuban Missile Crisis (Boston, 1971); Morton Halperin, with Priscilla Clapp and Arnold Kanter, Bureaucratic Politics and Foreign Policy (Washington, D.C., 1974); and Kam, Surprise Attack, pp. 163, 176–86.

¹¹Although expositions of rational-actor theory emphasize different factors, they usually share theoretical assumptions. Foremost among these is that individuals use information in an honest fashion to choose the best alternative among a set of options. Four other assumptions are also prominent. First, individuals identify all possible alternatives, or at least they search for alternatives until the process begins to waste resources. Second, individuals estimate the probability that an alternative will be successful and assess the impact of a chosen alternative on the values they seek to optimize. Third, decision makers integrate new information into their effort to make an effective decision, allowing them to make more sophisticated judgments about the implications of various alternatives. Fourth, individuals realize the need to make choices between the benefits and costs of competing alternatives to select the best policy. Even though individuals can only approximate a rational decision-making process in real life, rational-actor theory provides a highly demanding set of criteria that is still advanced as an ideal way to make decisions; see Allison, Essence of Decision, pp. 28–38; Richard Ned Lebow, Between Peace and War (Baltimore, 1981), p. 101; Irving L. Janis and Leon Mann, Decision Making: A Psychological Analysis of Conflict, Choice and Commitment (New York, 1976), pp. 13, 29; Janice Stein and Raymond Tanter, Rational Decision-Making (Columbus, 1980), p. 27; Helmut Jungermann, The Two Camps on Rationality, in Judgment and Decision Making, ed. Hal R. Arkes and Kenneth R. Hammond (Cambridge, 1986), pp. 627–641; and Alexander L. George, Presidential Decisionmaking in Foreign Policy: The Effective Use of Information and Advice (Boulder, Colo., 1980), pp. 22–23.

¹²Lebow, Between Peace and War, p. 105. For a discussion of premature cognitive closure, see Robert Jervis, Perception and Misperception in International Politics, (Princeton, 1976), pp. 187–191.

¹³Jervis, Perception and Misperception, pp. 117–124; Perceiving and Coping with Threat, in Psychology and Deterrence, ed. Jervis et al., pp. 18–24; and Political Decision Making: Recent Contributions, Political Psychology 2 (Summer, 1980), 86–100; Ole R. Holsti, The Belief System and National Images: A Case Study, The Journal of Conflict Resolution 6 (1962), 244–252; Wohlstetter, Pearl Harbor, pp. 397–401; Handel, Intelligence and the Problem of Strategic Surprise, pp. 249–251; Robert Axelrod, Structure of Decision: Cognitive Maps of Political Elites (Princeton, 1976); and Richard E. Neustadt and Ernest R. May, Thinking in Time (New York, 1986).

¹⁴Wohlstetter, Pearl Harbor; and Betts, Surprise Attack. The damage done by international crises on the ability of statesmen to communicate and interpret intended and unintended signals has also been identified as a factor in intelligence failure in Lebow, Between Peace and War; Windows of Opportunity: Do States Jump through Them? International Security 9 (Summer, 1984), 147–186; and Nuclear Crisis Management: A Dangerous Illusion (Ithaca, 1987); Jack Snyder, Civil-Military Relations and the Cult of the Offensive, 1914 and 1984, International Security 9 (Summer, 1984), 108–146; and Glenn Snyder and Paul Diesing, Conflict among Nations (Princeton, 1977).

¹⁵Allen S. Whiting, China Crosses the Yalu: The Decision to Enter the Korean War (Stanford, Calif., i960); Whaley, Codeword BARBAROSSA; and Handel, Military Deception in Peace and War.

PART I

"THE BIG VICTORY,

THE GREAT TASK"

[1]

The Communist Debate over Strategy

One of the many questions about the Vietnam War that remains to be settled is why the North Vietnamese decided to launch the Tet offensive. The question is intriguing because the communist offensive was both a dismal military failure and a brilliant political success. The U.S. military quickly recovered from the surprise it suffered and decimated the Vietcong (VC) forces that bore the main burden of the attack. In the aftermath of the offensive, however, the American public and the Johnson administration seriously questioned the costs and objectives of the war. In this respect, the Tet offensive acted as a catalyst, setting in motion a chain of events that would lead to negotiations, a halt in the bombing of North Vietnam, and a deescalation of the U.S. combat role in South Vietnam. Tet did not end the war for the communists, according to Richard Betts, but it created the necessary conditions for political victory.¹

Although students of the Vietnam War do not dispute the military outcome of the Tet offensive or its political impact, they have not achieved a consensus about the attack’s objectives. Two interpretations of communist goals have dominated the debate. The first maintains that the shift created in American public and elite opinion was an intended rather than an unintended consequence of the offensive. Many leading commentators on the war, for example, Gen. William C. Westmoreland, the commander of the U.S. Military Assistance Command, Vietnam (MACV) at the time of the offensive, Col. Harry G. Summers, Leslie Gelb, and Richard Betts, claim that the attitudes of the American public and members of the Johnson administration were the ultimate targets of the offensive.²

The second interpretation maintains that an improvement in the military situation or even the immediate domination of South Vietnam was the primary objective behind what the communists called their general offensive-general uprising. Stanley Karnow, for example, notes that, at a maximum, the communists hoped to overthrow the Saigon regime and replace it with a neutralist coalition dominated by the VC. Once in place, the new regime would work to eliminate U.S. presence and put Vietnam on the path to unification under communist control. U. S. Grant Sharp, former commander in chief, Pacific (CINCPAC), believes that the communists intended to destroy the South Vietnamese administrative structure so that it would no longer function even with U.S. aid. Sharp also notes that the North Vietnamese hoped for a large-scale defection of South Vietnamese troops, facilitating the communist domination of large portions of the country. According to Patrick McGarvey, Tet was intended to improve the position of the North Vietnamese in future negotiations by placing the two northernmost South Vietnamese provinces under communist control, setting the stage for the eventual domination of the country.³

Neither of these interpretations is particularly compelling. The first is misleading because it ignores the probable existence of a communist theory of victory and seems to suggest that the North Vietnamese expected to tip the political scales in their favor just by demonstrating their willingness to stand up to their opponents’ firepower. It fails to account for any realistic North Vietnamese military objectives, the logical prerequisite for an effort to influence American opinion. In contrast, the second explanation, which focuses on the military objectives of the offensive, fails to acknowledge the deteriorating situation faced by the North Vietnamese and VC forces on the eve of Tet. Moreover, both interpretations largely ignore the insights into communist objectives offered by the concept of a people’s war, especially the Vietnamese version of this strategy.⁴