BOCA RATON, Fla. — President Barack Obama and Mitt Romney clashed repeatedly over foreign policy here Monday night, with the president arguing assertively that Romney has lacked the consistency or clarity of vision to lead the country while the Republican nominee charged that Obama has been weak and ineffective in the face of growing turmoil in the world.

The two candidates differed most sharply over the president's handling of the uprisings in the Middle East, his efforts to prevent Iran from obtaining nuclear weapons and his treatment of Israel. But often they seemed to find common ground on some of the policies the administration is pursuing.

With the debates over, the two candidates and their campaigns now begin a two-week sprint to Election Day. The campaigns will be focused on a relative handful of states with two objectives: winning over the few remaining undecided voters with a last barrage of television ads and intensifying efforts to get their identified supporters to the polls — either during early voting periods or on Nov. 6.