Why Was the Admission of Red China to the UN No Longer an "Important Question," Requiring a Two-Thirds Vote for Approval?

In 1945, China became a charter member of the United Nations. In 1949, the government was overrun by the Communists and was forced to relocate to Taiwan. For many years, the Communists sought membership in the United Nations, but through the 1950's, proposals to admit the Red Chinese were always defeated.

Beginning in the 1960's, the question became closer. During that time, the United States secured, by a majority vote, the adoption of a resolution declaring the admission of Red China an “important question,” which required a two-thirds vote. Since the Red Chinese did not have the support of two-thirds, proposals to admit Red China to the United Nations were defeated.

Finally, in 1971, the charade ended. The resolution to declare the matter an “important question” was defeated, and the motion to admit the Red Chinese, and to expel Taiwan, was passed.

Why did the nations of the world refuse to go along with the “important question” technique? And how much was it costing the United States to keep them in line during the 1960's?