>>508506729yeah basically this
American no longer wages war like we use to. If America committed the majority of its military forces to a target, I don't think any country in the world would be able to defend against them, but we don't do that. We send the minimum, and hope it works out, because the people won't back a full-scale war. Congress won't back a full-scale war. A full-scale war won't ever happen again, unless it's against another large nation like Russia or China which necessitates it.
We committed only about 15% of our military power to Vietnam. We committed half that to Afghanistan. Of course if you include the military forces stationed elsewhere during those conflicts, or in support roles, the percentage goes up, but in terms of actual boots/tires on the ground and birds in the air, the number was just a fraction.
We were fighting them with one hand and nothing else, because the people didn't want to see our country sending in 75-80% of our might and brutalizing some dirtpoor nation. You can't justify that kind of invasion unless the nation's survival is at stake.