BEIJING — From the moment Turkey announced plans two years ago to acquire a long-range missile defense system, the multibillion-dollar contract from a key NATO member appeared to be an American company’s to lose.


For years, Turkey’s military had relied on NATO-supplied Patriot missiles, built by the American companies Raytheon and Lockheed Martin, to defend its skies, and the system was fully compatible with the air-defense platforms operated by other members of the alliance.


There were other contenders for the deal, of course. Rival manufacturers in Russia and Europe made bids. Turkey rejected those — but not in favor of the American companies. Its selection last month of a little-known Chinese defense company, China Precision Machinery Export-Import Corp oration, stunned the military-industrial establishment in Washington and Brussels.