This article provided by our friends at Share America/ US Department of State.

The Cuban missile crisis of October 1962 was the moment that the United States and the Soviet Union came closest to nuclear war. The conventional wisdom is that decision-making occurred “with relatively little input from the respective bureaucracies  typically involved in the foreign policy process.”

In fact, the lawyers in the State Department’s Office of the Legal Adviser played a crucial role in crafting a strategy that would simultaneously project American strength and maximize decision-makers’ political flexibility.

A brewing crisis

In July 1962, the Soviet Union secretly agreed with the Castro regime to place medium and intermediate range ballistic nuclear missiles in Cuba, a mere 90 miles off of the Florida coast, targeting the entire eastern and middle United States and a large portion of Mexico, Central and South America.

A right side view of two vehicle-mounted Soviet R-14 Chusovaya (NATO code name SS-5 Skean) intermediate-range ballistic missiles.

In early September 1962, U.S. intelligence discovered evidence of a general Soviet arms buildup, including IL-28 “Beagle” tactical nuclear bombers.

On September 4, 1962, the White House issued a statement  that “All Americans, as well as all of our friends in this hemisphere, have been concerned over the recent moves of the Soviet Union to bolster the military power of the Castro regime in Cuba,” that approximately 3,500 Soviet military technicians were “in Cuba or en route,” but that there was “no evidence” of “offensive ground-to-ground missiles; or of other significant offensive capability either in Cuban hands or under Soviet direction and guidance. … Were it to be otherwise, the gravest issues would arise.” Then-President John F. Kennedy promised that the United States “shall continue to make information available as fast as is obtained and properly verified.”

On October 3, 1962, the Congress passed a joint resolution  declaring that “the United States is determined to prevent by whatever means may be necessary, including the use of arms, the Marxist-Leninist regime in Cuba from extending, by force or the threat of force, its aggressive or subversive activities to any part of this hemisphere.”

On October 14, 1962, a U.S. U-2 aircraft took several pictures clearly showing sites for nuclear-armed, medium-range and intermediate-range ballistic missiles under construction in Cuba.

The president and his advisers considered a range of options. Some, including all members of the Joint Chiefs of Staff, argued for an air strike to destroy the missiles followed by a U.S. invasion of Cuba. Others argued for warnings to Cuba and the Soviet Union without action. The president decided upon a middle course. On October 22, 1962, he ordered a naval “quarantine” of Cuba.

The use of the word “quarantine” legally distinguished this action from a blockade, which assumed a state of war existed. The use of “quarantine” instead of “blockade” also enabled the United States to receive the support of the Organization of American States. The goal was to prevent further military deliveries to Cuba and to apply pressure on the Soviet Union to remove the existing missiles and bombers.

That same day, the president sent a letter  to Soviet Premier Nikita Khrushchev declaring that the United States would not permit offensive weapons to be delivered to Cuba and demanding that the Soviets dismantle the missile bases already under construction or completed and return all offensive weapons to the Soviet Union.

The letter was the first in a series of direct and indirect communications  between the White House and the Kremlin throughout the remainder of the crisis. That evening, Kennedy announced to the nation via a televised address  that the United States had confirmed that a series of offensive Soviet missile sites were in “preparation” and that their purpose “can be none other than to provide a nuclear strike capability against the Western Hemisphere.”

On October 23, 1962, the president issued Proclamation 3504 , “Interdiction of the Delivery of Offensive Weapons to Cuba.” The order included “Surface-to-surface missiles; bomber aircraft; bombs, air-to-surface rockets and guided missiles; warheads for any of the above weapons; mechanical or electronic equipment to support or operate the above items; and any other classes of materiel hereafter designated by the Secretary of Defense for the purpose of effectuating this Proclamation” and provided that “to enforce this order, the Secretary of Defense shall take appropriate measures to prevent the delivery of prohibited materiel to Cuba, employing the land, sea and air forces of the United States in cooperation with any forces that may be made available by other American States.”

On October 25, 1962, the U.S. military was ordered to DEFCON 2, the alert state just short of nuclear war and the highest-level alert ever issued in U.S. history.

A Russian IL-28 bomber.

On October 28, 1962, the Soviet Union announced the dismantling of its missiles in Cuba.

On November 20, 1962, following the Soviet Union’s agreement to withdraw the IL-28 nuclear bombers from Cuba, the president terminated the quarantine.

How the legal adviser empowered U.S. decision-makers

The State Department’s Office of the Legal Adviser played a pivotal role by creating options for the president and other U.S. decision-makers to shape U.S. diplomatic strategy.

In September 1962, after it became clear that the Soviet Union was rapidly building an offensive military capability in Cuba, the White House tasked the State Department’s Office of the Legal Adviser with assessing the United States’ international legal obligations and commitments. The Kennedy administration thought that the best option available — short of military invasion or an aerial campaign — was to prevent any additional military equipment  from reaching Cuba.

A problem was that Secretary of State Dean Rusk and Vice President Lyndon Johnson had both recently testified to Congress that a blockade of Cuba would be “an act of war.” Legal Adviser Abram Chayes advised against such a blockade in a now-declassified legal memo:

Accordingly, the administration shifted from the idea of a blockade to a “defensive quarantine.” The State Department’s Office of the Legal Adviser had proposed that shift during a meeting of the Executive Committee of the National Security Council on October 19, 1962. While a defensive quarantine would not be an act of war, it would still be a use of force. Thus, a defensive quarantine would be analyzed under Article 2(4) of the United Nations Charter : “All Members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state, or in any other manner inconsistent with the Purposes of the United Nations.”

The Office of the Legal Adviser analyzed the word “other” in Article 2(4) to mean that only threats or uses of force inconsistent with the purposes of the United Nations were prohibited. In other words, even measures that might impinge on the territorial integrity or political independence of a state would not necessarily violate Article 2(4) as long as such measures were not inconsistent with the purposes of the U.N. The purpose of the quarantine was to safeguard peace and stability in the region, and Article 52 of the U.N. Charter affirms that regional organizations could enact their own solutions for peace and security.

The Office of the Legal Adviser therefore turned to the Organization of American States Charter and the Rio Treaty . Article 6 of the Rio Treaty sets forth a broad authorization for regional security: When a situation “might endanger the peace of America,” the Member States would “meet immediately in order to agree on … the measures which should be taken for the common defense and for the maintenance of the peace and security of the [American] Continent.” Based on that, the State Department concluded that a defensive quarantine — and even a blockade — authorized by the Organization of American States would be consistent with the purposes of the U.N. and international law.

On October 23, 1962, the same day that the president issued Proclamation 3504, the secretary of state presented in person to the Organization of American States  to invoke the Rio Treaty and introduce a draft resolution to authorize a use of force for the quarantine:

The member states unanimously adopted the U.S. resolution, authorizing them to “take all measures, individually and collectively including the use of armed force which they may deem necessary to ensure that the Government of Cuba cannot continue to receive from the Sino-Soviet powers military material and related supplies which may threaten the peace and security of the Continent and to prevent the missiles in Cuba with offensive capability from ever becoming an active threat to the peace and security of the Continent.” Notably, Cuba had been suspended  from the Organization of American States earlier that year because its communist government threatened the region.

The United States’ deployment of a quarantine consistent with international law proved highly effective. On October 24 and 25, some Soviet ships turned back from the quarantine line, while others were stopped by U.S. naval forces but allowed to proceed after confirming they were not carrying offensive weapons. The quarantine helped convince Soviet dictator Nikita Khrushchev to come to the negotiating table. By October 28, the United States and the Soviet Union reached a deal for the removal of the Cuban missiles, effectively ending the crisis.

Lessons learned

The Cuban missile crisis case study proves that creative legal advice can help counter U.S. adversaries, build international coalitions and preserve peace. Then, the Office of the Legal Adviser developed practical alternatives providing American political and military leaders maximum flexibility in action while at the same time informing and supporting the administration’s public diplomacy strategy. Today, the Office of the Legal Adviser provides the legal advice needed to help our clients advance American interests worldwide, and the results are evident: from Gaza to the Caucasus to eastern Africa and beyond, the president, the secretary of state, and other senior policymakers are leveraging the Office of the Legal Adviser’s innovative ideas to help make America safer, stronger and more prosperous.

For the Silo, Reed D. Rubinstein/ Legal Adviser of the U.S. Department of State.

Supplemental- How Canada was affected by the Crisis

The Cuban Missile Crisis heightened military readiness in Canada, strained U.S. Canada relations, and had lasting political implications for the Canadian government.

Military Readiness and Alert Status

During the crisis, Canada faced a direct threat from the Soviet missiles stationed in Cuba, capable of reaching both the United States and Canada. In response, Canadian armed forces were placed on heightened alert. National Defence Minister Douglas Harkness requested that Canadian military units raise their alert level to the “Ready State”, equivalent to the U.S. DEFCON 3. This decision was delayed due to internal cabinet debates, reflecting the cautious approach of Prime Minister John Diefenbaker, who was hesitant to fully commit Canadian forces without U.S. approval.

Political Implications

Diefenbaker’s indecisiveness during the crisis soured relations with the United States. His reluctance to provide unequivocal support for U.S. actions, such as the naval blockade of Cuba, led to tensions between the two countries. Diefenbaker’s government faced criticism for its handling of the crisis, which contributed to the its downfall in the 1963 election. The crisis highlighted the complexities of Canada-U.S. relations, particularly regarding military cooperation and sovereignty issues, as Diefenbaker sought to assert Canada’s independence in foreign policy.

Military Cooperation and Lessons Learned

The crisis also underscored the importance of military cooperation between Canada and the United States. Canadian naval forces participated in patrols to locate Soviet submarines in the North Atlantic, demonstrating the close coordination between the Royal Canadian Navy (RCN) and the U.S. Navy. The experience gained during the crisis influenced future Canadian military operations and emphasized the need for readiness in the face of potential threats.

Conclusion

Overall, the Cuban Missile Crisis had a profound impact on Canada, affecting its military posture, political landscape, and diplomatic relations with the United States. The events of October 1962 served as a critical moment in Canadian history, sharing its approach to defense and foreign policy in the subsequent Cold War era.