Stv,
Imagine you, yourself, are in a situation, say a hostage situation or a terrible car accident, something that COULD theoretically happen in your apparently super moral country of Canada where no one does any wrong. There are two lives in this situation, both badly injured or about to be, one is a stranger, the other someone you love, your wife, your child, your mother etc. You are asked to CHOOSE who will live. 99% of people, in that situation, I would suspect would go with the loved one. You could offer to sacrifice yourself, but the human will to live is a basic drive. Now, it's HIGHLY immoral that you would choose the death of the stranger over the death of a loved one, however, attachments being what they are most people would do it without a second thought. Heck I KNOW I would choose my husband over a person I didn't know because their life doesn't, in the heat of the moment, directly influence mine.
Now what does this have to do with military actions? Everything. One of the BIGGEST things I hear is that the fight is kept over there, so that it doesn't come over here. So that our loved ones can go to the market without fearing for their lives, that we don't have to worry about IEDs on our daily car ride to the store or the doctors office etc. Most servicemen, DESPITE what you think, deploy not for the money or for bloodlust, but for the desire and drive to keep their loved ones safe from people wishing to do us and our way of life, harm. And yes, some of them volunteer for deployments but many times that is because they wish to keep their brothers safe. There literally is nothing worse then losing a friend/loved one and thinking you could have done something to change the outcome.
Now, we all wish the world was a peachy keen 1950's movie where world peace was a reality and everyone sang their nations version of koombaya around a campfire. It's not. Despite how badly you want it to be. This is reality, there are VERY real threats to this world, and very real world monsters on a power trip. I guaran-damn-tee you that most soldiers do not want to go to war any longer. However, until certain nations step off the crazy train that involves mass murdering their own women and children and subjugating entire factions of the population on the basis of religion, skin color, language or genitalia, well, frankly, that's not a reality. I wish the people of these nations, and the able bodied men in particular, would stop fleeing to Europe and finally stand up to the terrorists that are destroying their way of life, but they aren't, and their governments are so damn corrupt that as long as the money keeps flowing into the elites pockets they don't give a damn about the peasants.
It is very easy for you to sit in your Ivory Tower and judge all the "immoral" people in the world, but as others have pointed out, until you lose someone to irrational violence, or you yourself are put into a situation that is life or death, you will never be able to understand, and for your sake, I HOPE you are never in that situation. Instead you sit, like an old school Vietnam runner, in a foreign country, running your mouth about the immoral decisions people make here in the US. Are there problems with the military, oh hell yea, never going to disagree on that one. But, there are problems with EVERY company, government, job, etc out there. All an INDIVIDUAL can do, is make the right decision, for them, in the moment that it has to be made.
Human beings, after all, are not infallible.