There will always be war, or the stirrings of war somewhere in the world. That is not ideal, but it is reality. And that reality dictates that a nation be prepared to defend itself and wage war if necessary.
Men and women choose to enlist in military service of their own free will, and for the most part it is an honorable choice. An essential part of being a soldier is the discipline to follow orders, and a soldier takes pride in carrying out his/her duty.
Whether or not a soldier would have chosen for his country to engage a particular enemy becomes irrelevant, the discipline necessary to maintain a successful military means that every soldier, at every rank, must carry out their sworn duty, and as I said earlier, they usually take great pride in that.
Certainly military recruiters paint a glorious picture to young recruits, and of course they are going to highlight the benefits over the drawbacks, what prospective employer wouldn't? But how does that compare to the recruiting campaigns of the terrorists? They sell them on the idea that killing anyone who opposes their particular brand of religion ensures them an everlasting life of comfort and glory, surrounded by youg virgins. The families of suicide bombers are considered worthy of great honor, and are even given money, for raising their child to be "fine and honorable" suicide/murderer!
Whether or not you agree with a particular war, at least the volunteer soldier who signed up to protect and defend his/her country did so with the idea that it is a noble cause, that there is honor in putting your life on the line for your country and all that it stands for.
The extremist murderers (no I don't view them as "soldiers" or "insurgents" they are murderers in my book)have no desire to bring better living conditions or freedom to other peoples, most of them don't even have a country they can claim, just the desire to kill, and almost from birth they are fed a diet of hatred and the "logic" that it is somehow honorable to kill anyone who doesn't agree with you.
So, if there were no evil people, no one with a desire to kill everyone who didn't agree with them, no one with the desire to suppress freedom of speech, worship, and thought, there would be no need for young men and women to fight an die in wars. But until that time (which none of us are likely to ever see)people will enter into military service, and they will consider it an honor to put their lives on the line for the principles their country was founded on, even to the point of losing their life. I say we respect their decision, and be thankful that there are those who choose to stand in harms way for their country.