On April 15, 1969, North Korea shot down an American EC-121 reconnaissance aircraft. The incident has special meaning in the history of US-North Korea relations. 

The EC-121 attack, which killed all 31 passengers on board, was the most aggressive action North Korea has ever taken against the United States outside of the Korean War. Despite being a well-documented case of North Korea’s use of violence against the United States, we lack consensus about many aspects of the incident. Was it a deliberate attack, or an accident? Was it an anomaly, or part of the broader pattern of North Korean violence? And was its purpose mostly tactical (defending its airspace) or strategic (forcing a change in either US policy or that of China and the Soviet Union)?

Historians, at one time or another, have posited each of the above. Bernd Schaefer reflected in 2004 that “until further evidence is unearthed, Pyongyang’s rationale [for the EC-121 shoot down] remains unclear.” We remain at an impasse.

In today’s national security agenda, there is a pressing need to understand North Korea’s “theory of victory”—a term that broadly characterizes what North Korea believes is necessary and sufficient to deter adversaries, secure political goals, and control escalation in a crisis. Why? Even if North Korea seeks only survival, the important thing for regional stability and war-avoidance is to understand what the North Korean leadership believes about military signaling and “the diplomacy of violence” (to borrow Thomas Schelling). Even if North Korea has minimalist, defensive goals—which is debatable—it may still believe that the best defense is a good offense. And even if the DPRK seeks a diplomatic solution to its geopolitical insecurity, it may believe violence is a useful adjunct to its diplomatic strategy, as the United States once did during its failed coercive bombing of Vietnam.

Two newly released documents from the Soviet archives give us a chance to take stock of what we know about the EC-121 attack itself and, by extension, what that incident says about North Korea’s “theory of victory.”

What the Archives Say

Both documents capture meetings between North Korea and the Soviet Union on the day following the EC-121 attack, April 16, 1969. The first involved Heo Dam, North Korea’s Deputy Foreign Minister, with Soviet Ambassador to the DPRK N. Sudarikov. The second involved Pak Seong-Cheol, North Korea’s Foreign Minister and Deputy Chairman of the Cabinet of Ministers, who also met with Ambassador Sudarikov.

The two documents bear directly on the question of North Korea’s “theory of victory” vis-à-vis the United States. Heo Dam repeated an oft-heard refrain from Kim Il Sung that North Korea is “ready to respond to retaliation with retaliation, and total war with total war.” Heo also implied that the larger purpose of the EC-121 shoot down was the same as the capture of the USS Pueblo the year prior: “they [the Americans] have not drawn the proper lessons from the incident with the Pueblo.” That action, as a previous Sources and Methods piece discusses, was an act of military coercion aimed at a fundamentally political purpose.

The Soviet Ambassador had a more revealing conversation with Pak Seong-Cheol after meeting with Heo. Pak also recalled comparisons to the Pueblo incident, claiming that “if the Americans had decided to fight then, we would have fought.” Pak further stated “we wage firefights with the Americans in the area of the 38th Parallel almost every day. When they shoot, we also shoot…But no special aggravation arises from this.”

When Pak was pressed on whether North Korea understood the escalation risks of using violence against the United States, he replied “we’ve also shot down American planes before, and similar incidents are also possible in the future…It’s good for them to know that we won’t sit with folded arms.” Clarifying further, Pak conveyed:

If we sit with folded arms when a violator intrudes into our spaces, two planes will appear tomorrow, then four, five, etc. This would lead to an increase of the danger of war. But if a firm rebuff is given, then this will diminish the danger of an outbreak of war. When the Americans understand that there is a weak enemy before them they will start a war right away. If, however, they see that there is a strong partner before them, this delays the beginning of a war.

What It All Means

Each of the above statements directly address North Korea’s beliefs about force, deterrence, and compellence.

Pak Seong-cheol showed a firm belief in reciprocal, automatic violence when attacked, on the grounds that failing to retaliate will cause one to suffer future attacks. When he claimed that small attacks like the EC-121 shoot down help prevent general war, he was arguing that small acts of violence establish general deterrence; they are the “real” reason the United States does not invade. He believed, like Heo Dam, that the EC-121 shoot down would not lead to US retaliation because past similar attacks did not. The documents show Pak and Heo drawing inferences about the US unwillingness to retaliate from the latter’s handling of the Pueblo crisis the year prior.

In short, then, these documents reveal that North Korea believes provoking and attacking at lower levels of violence pays off at higher levels. They also reveal that North Korea, if attacked, will automatically reciprocate—generating a conflict spiral—because to do otherwise would bring on war anyway. Insofar as we can infer from these documents, North Korea’s theory of victory values offensive action and is highly reputational, as I argue in my own research on US-North Korea crisis bargaining. North Korea also makes inferences about the United States based on past actions and believes that the United States will make inferences based on past actions as well.

The documents also confirm several things historians have long debated. First, during this period, the Soviet Union exercised little to no control over North Korean foreign policy but did attempt to restrain North Korea on several occasions because it was worried that North Korea was inviting a renewed war on the Korean Peninsula. As Soviet Ambassador Sudarikov relayed in his reporting cable, the Soviets saw US military assets mobilizing immediately after the attack and feared “the possibility of a launch of a retaliatory strike…a direct military strike can also be expected of them.”

Soviet entreaties fell on deaf ears. Heo and Pak claimed North Korean behavior would be a reciprocal function of US behavior, period. This affirms a historical insight that bears repeating: influencing North Korea has always required dealing with North Korea directly, not its great-power patrons.

Second, despite later public evidence to the contrary, North Korea insisted that it shot down the EC-121 because it violated North Korean airspace; the attack was the implementation of a deterrent threat. The historical record tells us that at the time of the shooting, the EC-121 was 40 miles away from the North Korean coast (territorial airspace only extends 12 nautical miles). But the documents do not allow us to conclude why this discrepancy—between North Korea’s representation of the EC-121 violating its airspace and the reality that it did not—exists. It may be attributable to an expansive definition of what North Korea saw as its airspace. The United States thought adhering to the letter of international law boundaries was sufficient, but North Korea may have flouted legalistic claims in favor of interpretations based on spirit or intent. Or it may be a rhetorical device. Defensive attacks are more justifiable to external audiences.

Third, the documents continue to chip away at the narrative once popularized by Seymour Hersh that the incident was somehow an accident (which was based on the unverifiable assertion of an anonymous National Security Agency official). Nothing in how Heo or Pak explained the attack on the EC-121 characterizes the incident as anything but a deliberate act.

This does not necessarily mean it served a strategic purpose, but it does make the idea that a rogue military officer or squadron were the real cause seem less plausible. Heo put it bluntly: “our government has repeatedly warned the US imperialists that aggressors who dare to infringe on our sovereignty will be vigorously halted. These are not empty words.” Whether Kim Il Sung directly ordered the attack is a distinct question whose answer remains unclear, but North Korean officials, the day after the attack, framed it as deliberate and consistent with any prior direction provided.

These Soviet-era documents offer no “smoking gun” answers, but do provide an incrementally clearer picture of a crucial case in US-North Korean relations. They strongly imply that North Korea believes military force has political value, escalation is a reliable means of de-escalation, provocations help deter “US aggression,” and retaliating when attacked is essential to maintaining credible deterrence. Policymakers must heed this highly offensive and reputational “theory of victory,” or risk inadvertent war.