What is the X in X-mas?
The Republic of China; the government on the island of Taiwan. Established by Chiang Kai-shek in the late 1940s after he and his followers were driven from the mainland by the communists under Mao Zedong. Until 1979, the United States treated the Nationalist Chinese government as the legitimate government of all of China. Nationalist China and the United States still have unofficial diplomatic relations.
After the conquest of mainland China by communists led by Mao Zedong in 1949, Nationalist (anticommunist) leader Chiang Kai-shek led the remnants of his army to the island of Taiwan, where he established a government called Nationalist China, which the United States long recognized as the only legitimate government for all of China.