Tension mounted in late October 1961 when the Soviets mistakenly concluded that U.S. tanks
deployed at Checkpoint Charlie signaled an effort to break through the wall. Moscow deployed 10 tanks which squared off with
the U.S. tanks. Kennedy and Khrushchev privately defused the situation by agreeing that the Soviet tanks would withdraw first.
(Photo source: U.S. National Archives, Army Signal Corps Collection, #111-SC-591491)