For many weapons there is a limit to the length of time they can be flown (e.g. because of vibration damage); after this their safety or effectiveness is not guaranteed. This can be a problem if weapons designed for high intensity conflict are carried on multiple missions in a long counter-insurgency campaign.
...Where are they storing fuel, ordnance and unmanned aircraft? Where, when and how — in real time — are the Russian bombers, missiles and drones going to be coming against Ukrainian cities.