During fiscal year (FY) 2006, the Army's primary responsibility was to support ongoing coalition efforts in the Global War on Terrorism. The nation's priority of operations remained Afghanistan and Iraq in the U.S. Central Command's area of responsibility. In the continental United States, Army support for homeland security, Operation NOBLE EAGLE, continued to decline significantly from its peak just after the terrorist attack in 2001. Although eight thousand soldiers continued to serve in homeland security functions in 2006, the relaxed domestic security threat permitted the virtual elimination of reserve-component soldiers providing security at airports and other key sites vulnerable to terrorist attack. Instead, both active- and reserve-component soldiers focused their efforts on preparing for deployments overseas in ongoing operations in Central Asia. Because of the Global War on Terrorism, the Army's budget increased, ending more than a decade-long trend in budget decreases. The institutional costs attendant to supporting two contingency operations alone drove an increase in budget authority. This increase came in two discrete budget categories: the Army's annual budget appropriations and the supplemental appropriations to specifically fund operations. The active Army also obtained approval for a temporary increase in annual operating strength. Mobilization of reserve units and individual reservists for operations overseas yielded further increases in forces available.As operating strength increased, progress continued in transforming existing forces to thwart future threats. Former Army Chief of Staff General Eric K. Shinseki had made Army transformation the primary goal of his tour of duty at the beginning of the decade. Although the Global War on Terrorism eclipsed his concentration on adapting forces to deploy more rapidly and fight more intelligently on a battlefield, efforts remained under way on several projects to modernize and restructure existing Army forces. The Stryker Brigade Combat Teams had already entered the active force with a sixth brigade scheduled to undergo transition in 2008. The Pennsylvania Army National Guard also began the process of converting a brigade combat team from the 28th Infantry Division to the Stryker configuration. The Stryker units, however, remained an interim solution to the goal of fielding lighter units capable of deploying rapidly and hitting hard. General Shinseki had envisioned that an "objective force" that employed the Future Combat Systems (FCS) would fit the bill. While development of the main FCS vehicles continued, the Department of Defense endorsed the concept of "spiraling," that is, integrating the latest technologies that would be used by the Objective Force, such as new generations of drone aircraft, into the existing force as those technologies became available.