"President Barack Obama and U.S. military planners are on the defensive due to growing anxiety over a six-month-old strategy that lawmakers fear is failing to turn the tide in the costly, unpopular conflict. The strategy hinges on pouring U.S. forces into southern Afghanistan, the heartland of the Taliban insurgency, before starting a gradual withdrawal in July 2011, conditions permitting. Defense Secretary Robert Gates acknowledged it would be a ""long and a hard fight"" and that U.S. casualties would rise over the summer. But he assured skeptical lawmakers the new strategy had put the Afghan war on the right path. ""I think frankly that the narrative ... has been too negative. I think that we are regaining the initiative. I think that we are making headway,"" Gates said. Gates, a holdover from the George W. Bush administration, called for patience amid tough questions about the effectiveness of the war strategy from members of Congress, including Obama's fellow Democrats.