Is there some kind of switch that goes off in people's brains, when it comes to this war?
1. It wasn't completely about WMD's. The IWR makes that abundantly clear. If anything, the weapons PROGRAMS posed as great or greater threat.
2. We're at WAR. War. Ok? In war, men die. That's why it's to be avoided if possible. To go to war, and be engaged in a war means that there WILL be deaths, but that the resolution will be worth the price paid. Before the saber-rattling and the marching and the shooting, is the decision as to whether it's worth it. THEN, you commit to battle and keep fighting until it's been completed. To LEAVE the war before the objective is achieved is to spit on the graves of the lives casually at the start of the war. It's one thing to start a DIET and later decide "I guess I can't do this". You CANNOT do this with a war; giving up early means you are willing to waste lives for no reason at all. You might as well just shoot the soldiers in boot camp, because you wasted their lives.
3. It's the military and they are soldiers. Their job is NOT to maintain equipment, learn a trade or career, stand guard somewhere - their job is to fight the enemy to the death. They're paid to kill and the consequence is sometimes, they ARE killed. You can no more sign up to be a soldier and expect a life free from the perils of war than you can sign up to be a fireman and think, as in the movie "Pleasantville", your sole job is to rescue cats from trees, and be relieved from the dangers of firefighting.
It's a dangerous job, and everyone who signs up KNOWS this.
What did you THINK that paycheck was for, shining your shoes and looking spiffy in a uniform?