On Tuesday, Sen. Lindsey Graham (R-S.C.) said Obama was the "Neville Chamberlain of our time."

Neville Chamberlain’s mistake – acceding to a territorial compromise that did little to check Hitler’s continental aggression – is seen as a kind of original sin, a fatal act of foolishness and moral cowardice that had to be redeemed by nobler, braver men in the hideous years to come.

“This is the greatest appeasement since Chamberlain gave Czechoslovakia to Hitler,” said Sen. Mark Kirk (R-Ill.), reacting to the Iran deal last week.

“[President Obama] is doing this because of his very poor understanding of history and what happened to Neville Chamberlain.”