That's more of an ideological statement than an observation of facts or a conclusion that can be reached from history. Most casualties in the European theatre fell exactly when the opposing forces were capable, not when it was unbalanced as it was during the Blitzkrieg. But in the Soviet Union which had a capable military (they defeated the Nazis after all) the toll was staggering. And the Nazis were aware of the military capabilities of the Soviet Union but weren't deterred nevertheless. Japan wasn't deterred when it attacked Pearl Harbour nor Al Quaeda on 9/11. When the attacker for some reason believes they have a chance no military might forms a true deterrence. Other than that, a strong military always needs a raison d'être. It's politically-fiscally untenable having a huge military that just sits on their asses all day. So the reasoning is that the mere presence of a huge military force enables war. And when one looks at all the nations that have such, not just the US, that's exactly what happens.