Tehran has retaliated to the recent decision by the European Union to institute a phased-in ban on the import of Iranian oil by announcing it would no longer sell oil to France and Great Britain . . . the decision is largely symbolic as both nations import only small amounts of Iranian oil . . . other European nations, including Greece, Italy and Spain are far more dependent on Iranian sales . . . Tehran has threatened to end oil sales to hostile nations but may be reluctant to cut off sales to its more important European customers as the regime derives half of its budget from its energy sales . . . Iran has been taking a number of confrontational measures in recent weeks in response to growing international criticism of its weapons programs, including threatening to close the Strait of Hormuz and carrying out a series of highly publicized naval and ground force exercises . . . Tehran also has agreed to renewed talks on its nuclear program, a move almost certainly designed to buy time as the United States and European nations weigh additional punitive measures against the regime.