US Defense Secretary Robert Gates says he does not anticipate extending US troop deployments in Iraq beyond 15 months, which he called a "worst-case scenario" for the Pentagon. Gates endorsed the military's efforts to work with some Iraqi insurgents who initially fought against US forces. That may be the only way to bring peace to the bitterly divided nation, he said. "If we refuse to work with or ally with everybody who's been on the other side of the fence, then the prospects for making any progress in Iraq are pretty slim," Gates told Pentagon reporters at a news briefing. "Trying to bring some level of peace to Iraq is trying to persuade some people who have been fighting to stop fighting and become a part of a political process."