The Madiun Affair was a communist uprising in 1948 during the Indonesian National Revolution

Indonesian National Revolution

The Indonesian National Revolution or Indonesian War of Independence was an armed conflict and diplomatic struggle between Indonesia and the Dutch Empire, and an internal social revolution...

 in the town of Madiun

Madiun

Madiun is a city in the western part of the province of East Java Indonesia, an agricultural centre. It is the capital of the regency of the same name....

. Leftist parties led an uprising against the leaders of the newly-declared Indonesian Republic, but it was quashed by Republican forces.

On 18 September 1948 an 'Indonesian Soviet Republic' was declared in Madiun

Madiun

Madiun is a city in the western part of the province of East Java Indonesia, an agricultural centre. It is the capital of the regency of the same name....

, in the western part of East Java

East Java

East Java is a province of Indonesia. It is located on the eastern part of the island of Java and includes neighboring Madura and islands to its east and to its north East Java is a province of Indonesia. It is located on the eastern part of the island of Java and includes neighboring Madura and...

, by members of the Indonesian Communist Party

Communist Party of Indonesia

The Communist Party of Indonesia was the largest non-ruling communist party in the world prior to being crushed in 1965 and banned the following year.-Forerunners:...

 (PKI) and the Indonesian Socialist Party

Socialist Party of Indonesia

The Socialist Party of Indonesia was a political party in Indonesia from 1948 until 1960, when it was banned by President Sukarno.-Origins:...

 (PSI). Judging the time as right for a proletarian uprising, they intended it to be a rallying centre for revolt against "Sukarno-Hatta, the slaves of the Japanese and America". Madiun however was won back by Republican forces within a few weeks, and the insurgency leader, Musso, was killed. RM Suryo, the governor of East Java, as well as several police officers and religious leaders, were killed by the rebels.

The quashing of the rebellion ended a perilous distraction for the Revolution, and it turned vague American sympathies based on anti-colonial sentiments into diplomatic support. Internationally, the Republic was now seen as being staunchly anti-communist

Anti-communism

Anti-communism is opposition to communism. Organized anti-communism developed in reaction to the rise of communism, especially after the 1917 October Revolution in Russia and the beginning of the Cold War in 1947.-Objections to communist theory:...

 and a potential ally in the brewing global Cold War

Cold War

The Cold War was the continuing state from roughly 1946 to 1991 of political conflict, military tension, proxy wars, and economic competition between the Communist World—primarily the Soviet Union and its satellite states and allies—and the powers of the Western world, primarily the United States...

between the American-led 'free world' and the Soviet-led bloc.