We have been sold a story that goes like this: spend more on weapons, get more peace. But a strong government with an overpowering military didn't stop Luke Skywalker from joining the Rebel Alliance and launching an attack against the Death Star. It didn't stop Katniss from defying the Capitol. And it didn't stop Harry Potter and Dumbledore's Army from opposing the corrupt Ministry of Magic. La Résistance is an incredibly common trope.
Deterrence theory suggests that military strategy should entail more than just winning the war: it should deter conflict in the first place. By having a bigger military--a "bigger stick," if you will--you can avoid attacks because your opponent knows the damage they will incur in a fight is likely too big a price to pay. Typically applied to nuclear war, it certainly seems logical when dealing with certain actors--rational governments may avoid war with those who have nuclear bombs. Even in this context though, it is losing favor.