President Donald Trump knows his hike in tariffs for China's goods to 145 percent will up the ante in a trade war, but Beijing also holds a strong hand with its control of the materials critical for the United States defense industry. China first responded on April 3 to Trump's initial salvo of 54 percent levies on its exports by placing export restrictions on rare earth elements, which are key for the fighter aircraft that will form the backbone of the U.S. Air Force's next-generation fleet. Following a deal with Boeing, Trump has touted the F-47 as the successor to...