I mention this not because we should care more about #4,000 than #1 or #378 or #1,905, but because according to the Iraq and Afghanistan Veterans of America, only 28% of Americans surveyed knew how many thousands had died (most people thought it was 3,000 or fewer).
So. Now you know.
But don't worry. As Vice President Cheney pointed out today, they're all volunteers, and "the president carries the biggest burden, obviously."
Bigger, say, than the 2,200+ children who have lost a parent to this insanity. Obviously.