✔ 最佳答案
We just don't fight that kind of warfare anymore. Battlefields, thousands of grunts with rifles, trenches, 'going over the top'. That stuff's all history. Today the US's warmaking power is concentrated in aerial bombardment, because that's the kind of fighting that produces the fewest American casualties. Americans care about American casualties. Aerial bombardment--either carpet-bombing like we did in previous wars or drones like we're dong now--is a lot more expensive, plus it kills a lot more 'innocent bystanders', but Americans don't care so much about that.
Also we're learning that PTSD in returning vets is MUCH MUCH more common than we ever believed. Any red-blooded corn-fed American GI Joe is going to need help after bayonetting a few people in the guts. Just dropping a bomb on coordinates is so much easier, plus you can kill a lot of people faster.