As somebody who watched a 17 year old class mate hauled out of math class by the recruiters because he was failing in school and then 6 weeks later wound up in Viet Nam, I am in the category of 18 years old is too young to fight in a war in ground combat.
The third soldier to die in Iraq was a former student of mine. I still grieve even though as a junior high student, he was a royal pain.
Having said that, my father, like many others, enlisted at a young age to defeat Japan and ultimately end WWII. The war claimed my father in law, leaving my husband fatherless forever and altering his life in ways too numerable to speculate on. But I am so grateful that they defeated Hitler and Japan.
I think what it boils down to is is the war worth fighting? If it is,then I think we should all get our collective rear ends into the war in what ever way we can. When the Iranians were holding our people hostage, I was ready to enlist myself. After 9/11, had we immediately gone after the attackers instead Iraq, I think more of us would have enlisted, regardless of age.
But, how can we answer this question? The more I think about it, the crazier it makes me. Because how do you determine if a war is just if a President is lying to you about what our cause is? Ok - I give up.