Defense Secretary Robert Gates in January proposed a five- year spending plan with $78 billion of net savings from canceling some programs, reducing troop numbers and cutting overhead. Republicans backed Gates’s goal in a budget plan that passed the House in April./…/Gates’s proposed reduction represents about 2.5 percent of Pentagon spending over five years and is little more than a “light cut,” said Todd Harrison, a defense analyst with the nonpartisan Center for Strategic and Budgetary Assessment research group in Washington.