At the time, the Hungarian government was a Soviet puppet. When the people rebelled against the government, the Soviets sent troops to support the government so that Hungary would stay in the Soviet sphere of influence.
the ussr wanted them to stay communist
Miguel Hidalgo (1753-1811)
They had Russia backing them. The Communists back then were all followers of the "Great Communist Revolution" in Russia started by Trotsky and Lennon They had a much larger army and got help from the USSR. -- Nova Net
Communist infiltration into South VN started it.
The Soviet Red Army liberated Hungary from the Nazis and afterwards the Soviets started to influence the domestic politics and from 1948, Hungary was forced to build Socialism as a transitionary period before Communism. When in 1956 the Hungarian Revolution broke out against the Soviet rule, the Soviets sent troops and tanks to destroy the revolution. They wanted to keep Hungary on their side, i.e. among the Communist countries. The Soviets were afraid that similar revolution would break out in the other Communist countries: Czechoslovakia, Bulgaria, Romania, Yugoslavia, German Democratic Republic, and Poland.
Budapest, Hungary
they started it to stop communist
I'm not sure when it started but I know it ended in 1923!!!
Austria-Hungary
The Hungarian Revolution of 1956 (Hungarian: 1956-os forradalom) was a spontaneous nationwide revolt against the government of the People's Republic of Hungary and its Soviet-imposed policies, lasting from 23 October until 10 November 1956. Soviet Union crushed the revolt. However the Hungarian Communist Party eased its own rule later on in order not to risk more trouble and Hungary therefore became the weak link in the communist chain when things started to go to pieces for the Eastern Bloc at the end of the 1980s.
Serbia and austria-Hungary
Harry Truman, upon signing NSC 68, a classified report detailing the communist threat and detailing a national security strategy now commonly referred to as "Containment".
Austria-Hungary started the war, therefore they entered the war July 28 1914.