What were the reasons for the breakdown in detente efforts?

U.S.-Russia detente ends. On January 2, 1980, in a strong reaction to the December 1979 Soviet invasion of Afghanistan, President Jimmy Carter asks the Senate to postpone action on the SALT II nuclear weapons treaty and recalls the U.S. ambassador to Moscow.

when world war i broke out across europe in 1914, president woodrow wilson proclaimed the united states would remain neutral, and many americans supported this policy of nonintervention. however, public opinion about neutrality started to change after the sinking of the british ocean liner lusitania by a german u-boat in 1915; almost 2,000 people perished, including 128 americans. along with news of the zimmerman telegram threatening an alliance between germany and mexico, wilson asked congress for a declaration of war against germany. the u.s. officially entered the conflict on april 6, 1917.