The August 23, 1958, conflict, known in Taiwan as the “823 Artillery Bombardment,” is commonly referred to by Americans as the “1958 Taiwan Strait Crisis” or the “Second Taiwan Strait Crisis,” distinguishing it from the first crisis triggered by the artillery bombardment on September 3, 1954. In 1966, the RAND Corporation, an American think tank, completed an analytical report on the Second Taiwan Strait Crisis titled “The 1958 Taiwan Straits Crisis: A Documented History.” This report sheds light on the early signs of the crisis,
…The first sign of a possible crisis in the Taiwan Straits came on June 30, 1958, when the Chinese Communists demanded a resumption of the Sino-American ambassadorial talks.
However, it is difficult to establish a strong connection between these events in hindsight. On the Nationalist side, it is possible that the Republic of China armed forces, through aerial reconnaissance or other intelligence channels, discovered unusual movements by the People’s Liberation Army. As a result, on July 29, the Chief of the General Staff, Shu-Ming “Tiger” Wang (王叔銘), declared a state of emergency. It was only during the July 29th air battle, known as the 729 Air Battle, that the Nationalist forces engaged in direct conflict with the Communist forces, and tensions gradually escalated.
Declassified documents from the Central Intelligence Agency (CIA) indicate that the United States may have detected the signs of the Taiwan Strait Crisis as early as late May 1958. A document titled “Further on the CHICOM Coast,” issued on May 28, requested aerial reconnaissance of the Chinese Communist Party’s coastal areas, leading the Chief of Naval Operations (CNO) to approach the CIA to deploy U-2 reconnaissance aircraft (CHALICE being the codename for the U-2 reconnaissance program). Unfortunately, the content from point 6 to point 9 of this document remains classified, leaving the details unclear.
On June 2, a document addressed to Richard M. Bissel Jr., who oversaw the U-2 reconnaissance program, mentioned that the Department of State had approved aerial reconnaissance of the Chinese coastal areas.
Another document from the same day, referring to Admiral Arleigh Burke, the Chief of Naval Operations, expressed strong support for the reconnaissance mission. The document mentioned Captain Weber, who may have been Captain George Weber of the United States Navy, serving as a staff officer in the Office of the Chief of Naval Operations.
Subsequently, the CIA’s detachment in Japan, known as Detachment C, moved the U-2 aircraft to Naha Air Base in Okinawa in mid-June and conducted Mission 6012 on the morning of June 19. The aircraft flew from Fuzhou (福州) into Chinese airspace, heading north to Shanghai (上海), and then retraced its path back to Fuzhou. The US Navy was eager to obtain the photographic intelligence from this mission. The declassified photographic interpretation report for the 6012 mission is available for download.
Following the 729 Air Battle, the likelihood of a larger-scale conflict erupting between the Nationalist and Communist forces increased. The CIA planned additional U-2 reconnaissance missions to monitor the latest developments across the Taiwan Strait. The originally planned Mission 6014, scheduled for August 8 to conduct reconnaissance over the Shanghai area, was canceled due to political considerations. Mission 6015, launched on the morning of August 19, was terminated two hours after takeoff due to a hydraulic system failure. Mission 6016, scheduled for the same day, was canceled due to unfavorable weather conditions in the target area.
On August 20, Detachment C executed Mission 6017 with another U-2 aircraft, flying over various provinces on the other side of the Taiwan Strait. It flew south to Guangzhou (廣州), north to Luqiao (路橋) in Zhejiang (浙江) , and even deeper into Gan County (贛縣) in Jiangxi (江西). The following mission coverage map shows the U-2 aircraft’s route, which turned south after passing Ningbo (寧波).
Three days later, the People’s Liberation Army commenced intense artillery shelling on Kinmen (金門) Island, triggering the 823 Artillery Bombardment and marking the beginning of the Second Taiwan Strait Crisis.