Most historians agree that the agreement between Mr Chamberlain and Hitler benefited the Brits as it gave them sufficient time to complete their arms buildup.
I am guessing that no agreement between Obama and Iran would have been acceptable to conservatives. Apparently, war is the only answer. I suggest every republican run in 2014 on the "Let's go to war with Iran" slogan. You will all find out that Americans do not want to go to war with Iran.