PRC forces shell Kinmen and take the Yijiangshan islands, prompting the United States and the ROC to conclude a Mutual Defense Treaty in December 1954 and the US Congress to pass the Formosa Resolution. The crisis subsides in 1955 without general war.
Why it mattersThe first crisis established the pattern the system still follows: pressure applied to the periphery rather than the centre, calibrated to test the strength of an outside commitment without triggering a war. Seventy years later the instruments have changed and the logic has not.