Which united states president secured a détente with both china and the soviet union, ended u. s. involvement in vietnam, and resigned after the watergate scandal?
a. jimmy carter
b. richard nixon
c. ronald reagan
d. george h. w. bush

in 1989, what event signified the beginning of the end of the soviet union?
a. the berlin blockade
b. the fall of the berlin wall
c. the election of gorbachev
d. the soviet loss in afghanistan