Why would congress not ratify the salt ii treaty?

a. russia reneged on its part of the treaty.
b. the iranian revolution stopped the treaty.
c. russian combat troops were found in cuba.
d. the soviet union invaded afghanistan.

Congress would not ratify the SALT II treaty because D) The Soviet Union invaded Afghanistan and C) Russian combat troops were found in Cuba. Because of these two reasons Congress did not ratify the treaty. Six months after signing the treaty, the Soviet Union invaded Afghanistan and the United States discovered that there was a Soviet Union brigade stationed in Cuba which led to the treaty not being ratified.