The Cuban Missile Crisis dramatically affected public perception and civil society movements in both the US and USSR, leading to a surge in awareness and concern about nuclear war. In the United States, the televised address by President Kennedy and the ensuing tense days of the crisis brought the reality of nuclear war into the living rooms of the American public. This heightened awareness sparked a significant increase in civil defence measures, including public drills and the construction of fallout shelters. The crisis also galvanized the anti-nuclear movement, leading to increased public advocacy for arms control and disarmament. In the Soviet Union, while the state-controlled media presented a different narrative, there was also an undercurrent of relief and a rethinking about the dangers of nuclear escalation. The crisis contributed to a more cautious public mood regarding nuclear brinkmanship and a subtle shift in the perception of the United States, not just as an ideological adversary but also as a potential nuclear threat.

The Cuban Missile Crisis had a significant impact on Soviet leadership and policies. Firstly, it exposed the limitations of Soviet nuclear capabilities and the risks of their foreign policy strategies. Premier Khrushchev's decision to place missiles in Cuba was initially seen as a bold move to redress the nuclear imbalance with the United States. However, the subsequent American response and the forced withdrawal of the missiles were perceived as a diplomatic defeat for Khrushchev, both internationally and within the Soviet Union. This contributed to his eventual ousting in 1964. Moreover, the crisis prompted a reevaluation of Soviet military strategies, particularly the risks associated with nuclear brinkmanship. It led to a more cautious approach in Soviet foreign policy and a greater emphasis on diplomatic solutions to conflicts with the West, setting the stage for the later era of détente.

The Cuban Missile Crisis had a profound influence on subsequent arms control and disarmament efforts, acting as a catalyst for several key treaties and agreements. The immediate aftermath saw the signing of the Partial Nuclear Test Ban Treaty in 1963, which prohibited nuclear tests in the atmosphere, underwater, and in space. This treaty marked the first step towards controlling the nuclear arms race. The crisis also highlighted the need for better communication and mechanisms to prevent accidental war, leading to the establishment of the hotline between Washington and Moscow. In the long term, the crisis set the tone for future negotiations on arms control, including the Strategic Arms Limitation Talks (SALT) and the Anti-Ballistic Missile (ABM) Treaty. These efforts reflected a growing recognition of the mutual benefits of arms control, both in reducing the risk of nuclear conflict and in stabilising the superpower relationship.

Other countries played significant but often behind-the-scenes roles during the Cuban Missile Crisis. Notably, Turkey and Italy, hosting U.S. Jupiter missiles, became indirect participants in the crisis. The Soviet demand for the removal of these missiles in exchange for withdrawing their own from Cuba highlighted the global nature of the Cold War's strategic balance. Additionally, countries like Canada and members of the Organisation of American States (OAS) supported the U.S. naval blockade, demonstrating a unified front against the Soviet action in Cuba. The United Nations, particularly through Secretary-General U Thant, played a mediating role, offering a platform for negotiation and communication between the two superpowers. These international dimensions underscored the global stakes of the crisis and the widespread fear of a potential nuclear war.

Domestic politics played a crucial role in shaping President Kennedy's decisions during the Cuban Missile Crisis. Kennedy, mindful of the political ramifications, was under immense pressure to adopt a strong stance against the Soviet Union, particularly from military advisors and hawkish members of Congress who favoured a more aggressive response. The failure of the Bay of Pigs invasion in 1961 had already put Kennedy in a politically vulnerable position, making him wary of appearing weak on communism or Soviet aggression. This domestic context influenced his decision to opt for a naval blockade instead of an immediate military strike, which could have escalated into a full-scale war. Furthermore, Kennedy's approach was also shaped by the need to maintain public confidence and political support, balancing the demands of a strong foreign policy against the risks of nuclear war.