Warsaw Pact invasion of Czechoslovakia happened on 1968-08-20.

the conflict from the Warsaw PAct inavison of Czechoslovakia was .....

The forces from Warsaw Pact nations, primarily Soviet Union, invaded Czechoslovakia in the summer of 1968. This invasion was known as the Warsaw Pact invasion of Czechoslovakia or the Prague Spring. It aimed to suppress the liberal reforms implemented by Czechoslovakia's government.

Czechoslovakia

That Alliance was called the Warsaw Pact. It was dissolved in 1989.