The First Taiwan Strait Crisis (also the Formosa Crisis, the 19541955 Taiwan Strait Crisis, the Offshore Islands Crisis, the Quemoy-Matsu Crisis, and the 1955 Taiwan Strait Crisis) was a brief armed conflict between the Communist People's Republic of China (PRC) and the Nationalist Republic of China (ROC) in Taiwan. The conflict focused on several groups of islands in the Taiwan Strait that were held by the ROC but were located only a few miles from mainland China. The crisis began when the PRC shelled the ROC-held island of Kinmen (Quemoy). Later, the PRC seized the Yijiangshan Islands from the ROC. Under pressure by the PRC, the ROC then abandoned the Tachen Islands (Dachen Islands), which were evacuated by the navies of the ROC and the US.

In 1949, the Chinese Civil War ended with the victory of the Communist People's Republic of China (PRC). The government of the Republic of China (ROC), controlled by ROC president Chiang Kai-shek and the Kuomintang (KMT), and 1.3 million anti-Communist Chinese supporters fled from mainland China. The ROC government relocated to the island of Taiwan. The territory under ROC control was reduced to Taiwan, Hainan, the Pescadores Islands (Penghu), a strip of territory along the China-Burma border and several island groups along the south-east coast of China. In April 1950, the PRC captured Hainan. ROC forces there evacuated to Taiwan in May 1950.

The People's Liberation Army (PLA) is the armed forces of the People's Republic of China (PRC) and the armed wing of the PRC's founding and ruling political party, the Chinese Communist Party (CCP). Besides the Central Military Commission (CMC) and several minor units directly under it, the PLA has five major service branches: the Ground Force (PLAGF), Navy (PLAN), Air Force (PLAAF), Rocket Force (PLARF), and the Strategic Support Force (PLASSF). The PLA can trace its origins during the republican era to the left-wing units of the National Revolutionary Army (NRA) of the Kuomintang (KMT) when they broke away on 1 August 1927 in an uprising against the nationalist government as the Chinese Red Army before being integrated into the NRA as units of New Fourth Army and Eighth Route Army during the Second Sino-Japanese War. The two NRA communist units was reconstituted into the PLA on 10 October 1947.A majority of military units around the country are assigned to one of five theater commands by geographical location. The PLA is the world's largest military force (not including paramilitary or reserve forces) and constitutes the second largest defense budget in the world. It is also one of the fastest modernizing militaries in the world, and has been termed as a potential military superpower, with significant regional defense and rising global power projection capabilities.PRC law explicitly asserts the leadership of the CCP over the armed forces of China and designates the CMC as the nationwide military command of the People's Republic of China. The Party CMC operates under the name of the State CMC for legal and governmental functions and as the ceremonial Ministry of National Defense (MoD) for diplomatic functions. The PLA is obliged to follow the principle of the CCP's absolute civilian control of the military under the doctrine of "the party commands the gun" (Chinese: 党指挥枪; pinyin: Dǎng zhǐhuī qiāng) taken from a speech given by Mao Zedong during an emergency meeting of the top party leadership on the 7th of August 1927 at the beginning of the Chinese civil war. In this sense, the PLA is not a national army of the type of traditional nation-states, but a political army or the armed branch of the CCP itself since its allegiance is to the party only and not the state or any constitution. Its commander-in-chief is the Chairman of the Central Military Commission (customarily also the General Secretary of the Chinese Communist Party).Since 1949, China has used nine different military strategies, which the PLA calls "strategic guidelines". The most important came in 1956, 1980, and 1993. In times of national emergency, the People's Armed Police (PAP) and the China Militia act as a reserve and support element for the PLAGF. Politically, the PLA is represented in the National People's Congress with 294 deputies, all of whom are CCP members.