What political development led to the beginning of the cold war

The Soviet Union broke promise/lead to Cold War

Explanation:

Basically the soviet union made an agreement with the U.S and they did not keep their promise to sign the treaty and a war out broke with the both of them which lead to the cold war

The principal cause of the war was whether or not slavery was to be expanded into newly acquired lands in the west. After Abraham Lincoln won the November 1860 presidential election on a platform banning further expansion of slavery, seven slave states declared their secession from the country to form the Confederacy.

Explanation: