President Obama drew a line in the sand to the Iranian regime that at the end of 2009 they had better comply with the no nukes views of the United Nations. That was not successful. If it was a threat, it had no teeth, and if was a bluff, it didn't work and only made future pressurized negotiations more problematic. When an opponent likes to play hardball it is a mistake to make your image one of a superpower that cries wolf.
For an administration that prided itself as more stately than its predecessor, more open to world views and consensus building of international political leadership, the effect is devastating. To replace President Bush's carrot and stick approach you need a lot of carrots and the ability to cut off supply of them should your wishes not be complied with. In the world-governmental-view that some in the Obama administration seem to hold by, either you are able to make a consensus, or you have already lost control of the world to anarchistic rogue states. Effectively that is where the image of US Foreign Policy on Iran stands today.
The true pressure had to be applied to intransigent security council members who are staving off sanctions indefinitely. There needed to be a consensus before the Obama threat of sanctions, because by a world-government-first foreign policy the likelihood of military action replacing sanctions is staved off. Which means that if sanctions are not forthcoming, it is a rational supposition that military action isn't anywhere close to being just over the horizon.
President Obama had a nice set of cards, but not the cash to back it up. Iran is now waiting for him to fold his hand, and no longer worried that it should. That is not a good place to be.