WASHINGTON — President Barack Obama said in a nationally televised address Tuesday night that recent diplomatic steps offer "the potential to remove the threat of chemical weapons" inside Syria without the use of force, but he also insisted the U.S. military will keep the pressure on President Bashar Assad "and be ready to respond" if other measures fail. Speaking from the East Room of the White House, Obama said he had asked congressional leaders to postpone a vote on legislation he has been seeking to authorize the use of military force against Syria. Acknowledging the weariness the nation feels after a decade of war in Iraq and Afghanistan, Obama said, "America is not the world's policeman."