I think it's also possible he wants to do it after the election, since the giant leap in oil prices would hurt his chances at re-election.
From Excavator Blog
The writers at the Young Turks website raised the question: "Do you think Obama’s strategy to play both sides on Iran is right? Will it work to avoid a war?" This question is foolish for two reasons.
1) The war has already begun, and the totalitarian governments of America, England, and Israel are happily on the same side. As Ron Paul and others have said, sanctions against Iran are "an act of war." Economic war is war. The Israelis want to starve the Iranians, and Obama is okay with that.
2) Obama does not have a strategy to play both sides on Iran. He is fully on the side of the Israelis, and the war party in Washington. He wants to start World War III by attacking Iran, but he wants this war to appear as historically inevitable to the masses of America and the world. Israel and America must first stage a false flag attack in America to blame Iran, and destroy its image as a peaceful nation before attacking it. Otherwise, the war will not be politically or morally acceptable.
Obama is perfectly fine with having a war with Iran, but it has to be politically acceptable, and that takes "pressure to sink in," as he put it. Obama and his masters want war by stealth. They are trying to boil the Iranian frog in slow-motion, not throw it in an ocean of fire as the Israelis want.