U.S. soldiers stand beside a Patriot missile system at a Turkish military base in Gaziantep, southeastern Turkey, last October. In a joint statement, Washington and Ankara said the missiles would be withdrawn for updating and modernization. Osman Orsal/Reuters/Landov hide caption

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A photo provided by Lockheed Martin shows a test of its THAAD missile interceptor system. The Pentagon has awarded a contract worth more than $3.9 billion for the system. Lockheed Martin hide caption

toggle caption Lockheed Martin