Organizational structure of the United States Department of Defense of the Treasury. According to the U.S. Code, the Coast Guard is at all times considered one of the five armed services of the United States. During times of declared war (or by Congressional direction), the Coast Guard operates as a part of the Navy; this has not happened since World War II, but members have served in undeclared wars and conflicts since then while the service remained in its peacetime department. The Pentagon, in Arlington County, Virginia, across the Potomac River from Washington, D.C., is the Department's headquarters. The Department is protected by the Pentagon Force Protection Agency, which
Arlington County, Virginia completed in 2009. At the time of completion, the Turnberry Tower was tallest residential building in the Washington metropolitan area. In 2017, Nestle USA chose 1812 N Moore in Rosslyn as their US headquarters. In 2018, Amazon.com, Inc. announced that it would be splitting its "HQ2" second headquarters project between Arlington and Long Island City, New York. The Arlington HQ2 site is planned for the Crystal City neighborhood, anchoring a broader area of Arlington and the City of Alexandria that was simultaneously rebranded as National Landing. Arlington County is located in northeast Virginia and is surrounded by Fairfax County and