The Second Taiwan Strait Crisis began on August 23, 1958, involving military air and naval engagements between the People's Republic of China (PRC) and the Republic of China (ROC). The PRC initiated artillery bombardments on the ROC-controlled islands of Kinmen (Quemoy) and the Matsu Islands, while the ROC retaliated by shelling Amoy on the mainland. The United States intervened by supplying fighter jets, anti-aircraft missiles, and amphibious assault ships to the ROC but stopped short of fulfilling Chiang Kai-shek's request to bomb mainland China. An informal ceasefire came into play when the PRC declared on October 25 that they would only shell Kinmen on odd-numbered days, allowing the ROC to resupply their military on the even-numbered days.

The crisis was significant as it led to high tensions and risked drawing the United States into a broader conflict, potentially even a nuclear one. The U.S. faced diplomatic challenges, including the risk of alienating key allies like France and Japan. One notable escalation occurred in June 1960 when President Eisenhower visited Taipei; the PRC responded by intensifying their bombardments, leading to casualties on both sides. However, after Eisenhower's visit, the situation returned to its prior state of uneasy tension.

The crisis eventually de-escalated on December 2, when the U.S. discreetly withdrew its additional naval assets from the Taiwan Strait, allowing the ROC Navy to resume its combat and escort duties. While the crisis was considered a status quo result, it led U.S. Secretary of State John Foster Dulles to conclude that such a situation should not be allowed to happen again. This conflict was followed by another crisis in the Taiwan Strait only in 1995-1996, but no other crisis involving the United States has occurred in the region since 1958.