The United States has declared war on North Korea, according to North Korean Foreign Minister Ri Su Yong. In a brief news conference in New York on Sept. 25, Ri said that U.S. President Donald Trump's recent statements to the U.N. General Assembly were tantamount to a declaration of war and that all of the members of the United Nations clearly heard that it was the United States that first declared war on North Korea. Therefore, Ri argued, Pyongyang has a right to self-defense under the U.N. charter and would be justified if it were to shoot down U.S. strategic bombers, even outside North Korean territory.
Over the past week, the rhetoric between the United States and North Korea has rapidly escalated. North Korean leader Kim Jong Un responded to Trump's Sept. 19 U.N. speech by saying that Pyongyang was seriously considering the "highest level of hard-line countermeasures in history." The statement, accompanied by a picture of Kim sitting at a desk and looking intently into the camera — reminiscent of U.S. presidential addresses to the nation during times of crisis — was clarified later to suggest Pyongyang could carry out an atmospheric nuclear test in the Pacific Ocean.
Though much of the escalation has been rhetorical rather than concrete, both North Korea and the United States are inching closer to backing up their words with action to demonstrate their positions. The United States is openly discussing shooting down North Korea's next missile test, and North Korea has responded with what it considers to be an equivalent threat: the possibility of shooting down U.S. strategic bombers near the Korean Peninsula. Pyongyang has long equated the U.S. strategic bombers patrolling the peninsula to its own missile program and has warned that it could launch missiles to the U.S. coastline in a parallel show of range and force.
Trump's comments to the United Nations and the additional sanctions his administration recently imposed against North Korea could be seen as one step along the traditional path to U.S. military action. This path involves the U.S. making a strong case to the international community before resorting to unilateral action justified by the inability or unwillingness of the world to act. Washington has yet to take concrete action to suggest that it is preparing to strike. It has not changed its force posture or made moves to evacuate the 125,000-140,000 American civilians living in South Korea. Neither does North Korea appear to be significantly altering the positions of its forces, though it is exploiting increased U.S. threats to rally the North Korean population around the embattled government in Pyongyang.
Though neither the United States nor North Korea is making the formal movements that would suggest an imminent, purposeful military conflict, the fever pitch between the two and the increased shows of force do raise the likelihood that an accident or miscalculation could lead to conflict. North Korea and the United States have not agreed on basic rules of engagement for air encounters. So, should North Korea decide to scramble aircraft to intercept U.S. flights, even if it has no intent to engage, the potential for an accidental collision is high. In the region, aircraft have collided with U.S. aircraft in the past, last in 2001 off the Chinese coast, but military tension wasn't nearly as high then. U.S actions could be just as risky: If Pyongyang follows through on its threat to test a nuclear device in the Pacific, Washington could try to shoot down the launch, particularly if the weapon is on a trajectory that could bring it near the U.S. coast. In each scenario, tit-for-tat responses could lead to a rapid escalation unintended by either side.
Amid the intensifying standoff, signs of back-channel diplomatic efforts should be watched for, even if it appears that there is little space for a compromise that would satisfy both sides. Russia is working with North Korea diplomatically, and the North Korean Foreign Ministry official in charge of North America is in Russia this week, creating one such space for possible back-channel diplomacy. China's actions should also be watched closely. China's relationship with North Korea has been strained for the past several years, and many of the United States' warnings of military action could be meant more to convince China to take a stronger stand rather than to directly convince North Korea to change its course of action. Any changes in military postures will, of course, also be significant. These include the possibility that the United States could change the way it conducts its strategic bomber missions, by switching to stealth aircraft or expanding fighter escorts, for example.
The probability of intentional war is still relatively low without additional escalation, but the potential for accidental conflict is increasing. North Korea has threatened that in the near future it could test its missiles near the U.S. territory of Guam, test its missiles off the U.S mainland coast, intercept U.S. bombers near the Korean Peninsula and conduct an atmospheric nuclear test over the Pacific Ocean. The United States has been less specific in its threats, but it has increased its strategic bomber flights, has talked more openly about shooting down North Korean missiles and has discussed sending additional strategic assets to the region. And more physical action makes it more likely that accident and miscalculation could follow.
A previous version of this assessment misstated the facts surrounding the 2001 collision with a U.S. aircraft. The error has been corrected.