By ELLEN NAKASHIMA AND GERRY SHIH | The Washington Post | Published: April 7, 2021 In a secretive military facility in southwest China, supercomputers whir away, simulating the heat and drag on hypersonic vehicles speeding through the atmosphere — missiles that could one day be aimed at a U.S. aircraft carrier or Taiwan, according to former U.S. officials and Western analysts. The computers are powered by tiny chips designed by a Chinese firm called Phytium Technology using American software and built in the world's most advanced chip factory in Taiwan, which hums with American precision machinery, say the analysts. Phytium portrays itself as a commercial company aspiring to become a global chip giant like Intel. It does not publicize its connections to the research arms of the People's Liberation Army.