Final answer:
John Foster Dulles's policy of 'massive retaliation' meant that the US would respond to Soviet aggression with the overwhelming use of nuclear weapons, as a part of deterrence strategy during the Cold War.
Step-by-step explanation:
Under John Foster Dulles's policy of "massive retaliation," announced in 1954, the United States would retaliate against any Soviet aggression with the overwhelming use of nuclear weapons. This strategy was part of the broader Cold War tactic of deterrence, using the threat of massive nuclear response to discourage Soviet Union attacks. Secretary of State John Foster Dulles, along with President Dwight Eisenhower, shifted the focus of American defense strategy from maintaining large conventional military forces to developing and stockpiling nuclear weapons. The key idea was to make the threat of retaliation so great that the Soviet Union would not dare to carry out any attack against the United States or its allies.
Brinkmanship played a significant role in this strategy; it was the willingness to push a conflict to the edge of nuclear war without actually starting a conflict. The underlying belief was that neither side would risk mutual destruction, thus preventing any direct military conflicts between the superpowers. By 1960, the United States had significantly increased its nuclear warheads and developed a second-strike capability, ensuring it could respond to an attack even after sustaining an initial hit.
It's imperative to understand that while 'massive retaliation' and 'brinkmanship' sought to reduce the likelihood of war, they also increased the stakes, effectively making the threat of nuclear engagement an integral part of international diplomacy during this time.