What’s a Nuclear Hotline Good For Anyway?

Despite the proliferation of global communications, North Korea’s leaders have long pursued Tokugawa-like isolation from foreign influences. One of the few sanctioned exceptions is the crisis “hotline” that allows daily telephone conversations between North and South Korean military figures within the demilitarized border town of Panmunjom. Although the representatives from the two states talk from buildings only a few hundred feet apart, when the connection opened in 1971 it bridged oceans of violent separation. The hotline is the only channel for direct daily contact, and both sides used it regularly until early 2016, when North Korea stopped picking up.

That changed on Jan. 3, 2018, when Pyongyang’s representatives returned to the line, in conjunction with direct negotiations that started five days later between high-level officials of both states. But how significant exactly is the reopening of the hotline on the Korean Peninsula? Will the hotline reduce the risk of war, which has flared dangerously with repeated North Korean nuclear missile tests and flamboyant personal threats from both North Korean leader Kim Jong Un and U.S. President Donald Trump in the last year?

The history of previous nuclear hotlines offers important perspective. Their uses have been infrequent and often quite trivial, but their existence has discouraged rash behavior and encouraged confidence that crises can be managed short of war. Hotlines have facilitated signaling between adversarial states, and they have reduced the likelihood of dangerous miscalculations. They are valuable tools for diplomacy, especially in regions — like the Korean Peninsula — locked in conflict.

The Cuban missile crisis inspired the creation of the first nuclear hotline. During the two weeks in October 1962 when the United States and the Soviet Union approached the precipice of thermonuclear war, U.S. President John F. Kennedy and Soviet First Secretary Nikita Khrushchev struggled to control events. Khrushchev famously warned Kennedy: “If we succeeded in finding a way out of a dangerous situation this time, next time we might not safely untie the tightly made knot.”

The absence of direct communications between the two leaders tightened the knot as they struggled to understand each other’s motives and actions. Technological limitations, security concerns, and hostile Cold War attitudes made a point-to-point telephone line from the White House to the Kremlin impossible at that time. Instead, Kennedy and Khrushchev had to rely on intermediaries, including their ambassadors, who were underinformed and distrusted. They created special “back channels” to open new lines of negotiation, but these were often unreliable. Most significant unplanned events during the crisis, including the shoot-down of an American U-2 aircraft over Cuba, threatened to trigger major miscalculations and escalation.

Leaders had long relied on diplomats, spies, and other intermediaries for their communications with adversaries. The difference in 1962 was that the speed and depth of potential destruction in a thermonuclear world reduced the time for deliberation and increased the dangers of miscalculation. Kennedy and Khrushchev felt that they needed to talk with more urgency and sobriety than their predecessors.

They began by exchanging letters after the moment of acute crisis had passed. Then, in March 1963, the United States proposed “the establishment of direct and more secure communications” between American and Soviet leaders. On June 20, the two governments signed a memorandum of understanding in Geneva — the first arms control agreement of the Cold War — to create “a direct communications link” and “take the necessary steps to ensure continuous functioning of the link and prompt delivery to its head of government of any communications received by means of the link from the head of government of the other party.”

Implementation came quickly, reflecting the eagerness of leaders in both capitals. On July 13, 1963, the first Soviet-American hotline became operational. It consisted of two pairs of Teletype machines, linked by dedicated telegraph wires routed through Europe and under the Atlantic Ocean. The receivers sat in the Pentagon and the Soviet Communist Party Headquarters, where they were continuously manned to receive messages and send them immediately to the White House and Kremlin. The communication between leaders was still textual and indirect, but the time required was reduced from days and hours to minutes, and the possibilities for distortion were minimized. In 1967, the White House added a terminal, connected to the Pentagon receivers, and over the next four decades the technology was updated to include satellite communications, facsimile equipment, and eventually, in 2008, email.

The superpowers communicated through the hotline during numerous crises, beginning with the assassination of President Kennedy in November 1963, when Washington assured Moscow of political stability within the United States. The first extended exchange occurred during the 1967 Six-Day War, when American and Soviet leaders reassured one another that they would not intervene directly and would mutually sue for peace in the region. Similar communications during the Indo-Pakistani War of 1971, the Yom Kippur War of 1973, and the Cyprus crisis of 1974 clarified the lines of deterrence in conflicts that could have expanded beyond their regions. Communications during the Soviet invasion of Afghanistan in 1979 and the Polish Solidarity crisis of 1981 were less successful in defusing conflict between Washington and Moscow, but the exchange of messages limited possible miscalculations as Cold War tensions increased.

A direct voice link between the White House and Kremlin was possible by the 1990s, and it has largely replaced the textual hotline, although the latter still exists. American presidents now call allies and adversaries frequently, particularly during crises. In the last decade, they have begun to use cell connections in addition to landlines. Mobile technology, coupled with secure long-distance capabilities, facilitates reliable voice communications as never before. For leaders in Washington, the notion of a hotline has become more diffuse — there are many “hotlines.”

They remain essential for clarifying motives and actions during terrorist attacks, civil wars, and invasions — as well as a growing list of economic, health, and climactic crises. They also ensure confidential dialogue, free from the public posturing that makes crisis de-escalation difficult. Leaders must trust the sincerity of one another’s words for these connections to be meaningful, but their very existence deepens trust among those who use them.

Despite a decade of deteriorating relations between Russia and the United States, the leaders of the two countries continue to speak directly in moments of high tension, as Kennedy and Khrushchev could not during the Cuban missile crisis. Meanwhile, other countries have developed their own hotline technologies, modeled on the Soviet-American Cold War link. France and the United Kingdom built direct connections to Moscow in the late 1960s. In 1998, China established hotlines with Russia and the United States, followed by similar links with South Korea, India, and Vietnam after 2008. These links have received far less attention than the initial Soviet-American connection, but they are considered essential for clarifying intentions and maintaining stability in the many rivalries surrounding the Chinese mainland.

Two hotlines that have helped manage explosive rivalries, often on the edge of war, run between India and Pakistan and between the two Koreas. Modeled on the Soviet-American link, and encouraged by Washington, the India-Pakistan link provides secure communications between the two nations’ foreign secretaries “to prevent misunderstandings and reduce risks relevant to nuclear issues.” The India-Pakistan hotline has operated since 2004, and it has facilitated numerous moments of crisis de-escalation, assuring both sides that war is not imminent. The United States has facilitated the maintenance of this connection.

The same is true for the two Koreas, where the Red Cross (with American assistance), installed the first system in the early 1970s to assist with delivering aid and defusing recurring crises. The Korean hotline has kept the two governments talking, even in moments of acute conflict. It provides voice connections for military leaders on both sides, who otherwise have no method for exchanging messages directly.

The return of North Korea to its voice link with South Korea will not ensure peace, nor will it prevent disaster. Strategic hotlines have proliferated since the Cuban missile crisis to help manage conflicts involving adversaries with limited communications and extensive nuclear capabilities. So far, the hotlines have contributed to stability, confidence, and sometimes coordination. Despite peculiar efforts at isolation by a few nations, hotlines are integral to nuclear diplomacy in our contemporary world.