It is hard to know how exactly to support the troops in a war you don't believe should even be happening. Duane Shank gives one idea in Jim Wallis's blog, "God's Politics":
I’ve made reading the news each morning into a spiritual discipline. I read the
names in the almost daily U.S. casualty lists aloud and say a prayer for these
young men and women, their families and friends. Each one of them is a unique
child of God, with unique experiences and lives, now gone. Lifting them in
prayer has become a way to lament the continuing deaths.
I tried this earlier in the war, but it got very depressing. However, I never thought of it as a spiritual discipline. I think I will try this any time I read about a death in the paper. Whatever you think of the war, maybe you could join me.
You can see Shank's entire post at http://blog.beliefnet.com/godspolitics/2007/06/duane-shank-lord-have-mercy.html.