WASHINGTON — President Obama told an Israeli television station on Thursday that his administration believed it would take Iran “over a year or so” to develop a nuclear weapon, and he vowed that the United States would do whatever was necessary to prevent that from happening. Related Iran Chases U.S. Drone Over Persian Gulf (March 15, 2013) U.S. Says Greek Executive Evaded Sanctions on Iran (March 15, 2013) Connect With Us on Twitter Follow @nytimesworld for international breaking news and headlines. Twitter List: Reporters and Editors Less than a week before his first visit as president to Israel, Mr. Obama pledged to continue diplomatic efforts, but he promised that the...