Not the only example of this: Towards the end of the Vietnam war, the US had developed a fairly comprehensive counter-insurgency (COIN) program. By Iraq 2, they were pretty much only equipped for state on state warfare again and had to relearn COIN - and were actually doing an okay job by 2008. Ironically, given the withdrawal from Iraq, they&#x27;re probably going to have to relearn it again the next time they&#x27;re forced to put boots on the ground.<p>It happens quite regularly. Military forces have to adapt to the problem of the day.