Frank Schaeffer is a writer and most recently the author of "Faith of Our Sons -- A Father's Wartime Diary" (Carroll & Graf/Avalon, 2004). I never served in the military. Before my son unexpectedly volunteered for the Marines, I was busy writing my novels and raising my family, and giving little thought to the men and women who guard us. My attitude has changed. I did not choose to change. I was forced to. ... They are our sons, daughters, brothers and sisters. Sometimes shedding tears for strangers is a sacred duty. Sometimes it's all we can do.