Funny how most wars start off with assumptive optimism. [View all]

Civil War: Confederates thought the military controversy would be over in weeks.

First World War: Germany thought it could rely on strategic alliances and hubris to roll over small countries to avenge the assassination of Austria's future emperor.

Second World War: Germany (again) thought it could collect counties like charms on a bracelet, not forgetting it would be a cakewalk to roll in and out of Russia in a matter of weeks, only to be imprisoned by the deadly winter climate. (Operation Barbarossa).

Korean War: American military believed it was a mere policing maneuver, not a war.

Vietnam War: See Korean War.

2003 Invasion of Iraq: Knock off Sadam Hussain and easy-peasy.