WASHINGTON, March 9 - After years of campaigning against Hezbollah, the radical Shiite Muslim party in Lebanon, as a terrorist pariah, the Bush administration is grudgingly going along with efforts by France and the United Nations to steer the party into the Lebanese political mainstream, administration officials say.

The administration’s shift was described by American, European and United Nations officials as a reluctant recognition that Hezbollah, besides having a militia and sponsoring attacks on Israelis, is an enormous political force in Lebanon that could block Western efforts to get Syria to withdraw its troops.