I'm not sure what wars Bob was referring to either when he mentioned relatively low casualties. My point on casualties is a poorly prepared Army, like the one that invaded North Africa to fight the Germans, Vichy French, and Italians during WWII will take higher casualties than need/acceptable due to incompetence. I believe we'll be asking for a repeat of history if we rely on the militia.

U.S. Killed:

War of 1812 (approximately 20,000 KIA)
Mexican American War (13,283 KIA)
Spanish American War (2,446 KIA)
WWI (116,516 KIA)
WWII (405,399 KIA)
Vietnam (58,209 KIA)
Iraq (4,484 KIA)

These include numbers for non-combat deaths due to disease, etc.