Good points, but the thing is the public might very well see everything as one, the military not made up of various aspects, but as one, thus it is believed by some to be an outfit of thugs. Soldiers on the ground in fire fights accidentally (or intentionally) killing civilians, planes dropping bombs, the navy attacking, it all can look similar. The thing is to make it not seem like that.
The Iraqi war was compared to Vietnam a number of times, for moral, logistical and other reasons. Is it a fair label? It depends, certainly it is a war people seem convinced is wrong, and that is a big thing that links the two. The fact is that soldiers will seem like thugs until such a time as manipulative administrations do something about it. Maybe not every "psycho" can be caught, but most countries have more stringent entry requirements into say, becoming a police officer or teacher then being a soldier. More can be done that will both save lives of civilians and good soldiers while at the same time as aiding the reputaion of the armed forces in general.