WASHINGTON, Feb. 3 (Xinhuanet) -- The U.S. Defense Department saidon Friday that the country is engaged in a long war and the war is centered in Iraq and Afghanistan.

    In its congressionally-mandated Quadrennial Defense Review (QDR), the department said the United States has fought, since the Sept. 11, 2001 attacks, "a global war against violent extremists who use terrorism as their weapon of choice."

    The document said the war is now centered in Iraq and Afghanistan, but the United States will need to be prepared and arranged to successfully defend the country and its interests around the globe for years to come.

    "The war on terrorism requires the U.S. military to adopt unconventional and indirect approaches," it said.

    The review said that the United States must be prepared to wage the war in many locations simultaneously and for some years to come, and the Defense Department, while working to defeat these enemies, must also remain vigilant in an era of surprise and uncertainty and prepare to prevent, deter or defeat a wider range of asymmetric threats.

    In developing the review, the document said, senior leaders of the Defense Department worked throughout 2005 to test the conclusions of the 2001 defense review, apply the important lessons learned from more than four years of war against a global network of violent extremists, and test assumptions about the continuously changing nature of the world.

    The review reflects the thinking of Pentagon's senior civilian and military leaders, it said.

    The QDR defines two fundamental imperatives for the department: continuing to reorient the its capabilities and forces to be more agile in this time of war, to prepare for wider asymmetric challenges and to hedge against uncertainty over the next 20 years; and implementing enterprise-wide changes to ensure that organizational structures, processes and procedures effectively support its strategic direction.

    The review said the United States will build new long-range weapons in a hedge against potential rivals, and boost U.S. special forces to fight terrorism, strengthen homeland defense and step up efforts to thwart transfers of the deadliest weapons. Enditem