6h 9min, may 14, 1955 y - Warsaw Pact
Description:
The Warsaw Pact was a direct response to the formation of NATO, and had similar policies. Both organizations agreed that if any nations in their respective organizations got involved in a military conflict, they would aid them in that conflict. Members included communist countries like the Soviet Union, Poland, Hungary, Romania, and many others.https://en.wikipedia.org/wiki/Warsaw_Pact
Added to timeline:
Date:
6h 9min, may 14, 1955 y
Now
~ 70 years ago