U.S. Secretary of State John Kerry abandoned his bid to salvage a cease-fire aimed at easing Syria’s 5 1/2-year civil war, saying it was pointless to press ahead without a “major gesture” from Russia to end the violence.Kerry spoke to reporters after the U.S., Russia, Iran and other members of the International Syria Support Group met in New York on Thursday to discuss a truce that went into effect Sept. 12 but quickly unraveled.