In recent weeks, Barack Obama's foreign policy has been derided by critics who say he has almost nothing to show for his first 10 months in office.

After years of stalemate, negotiations over Iran's controversial nuclear development program seemed to progress last week when an Iranian delegation in Vienna agreed to the export and modification of its low-enriched uranium. The resulting optimism did not last. Officials in Tehran demurred, insisting that they needed more time to study the proposal and could not meet Friday's deadline to ratify the agreement. While Iran's stonewalling came as a disappointment to the United States, it did not come as a surprise. Over the past month, the White House has signaled that it is preparing a new, more severe round of sanctions in case current negotiations fail.