Why Is North Korea Turning More Aggressive?

North Korean leader Kim Jong Un recently shut down agencies working for unification with South Korea and seems to be ratcheting up bellicose rhetoric and activities. What is going on?

Kim Jong Un’s policies toward South Korea have become more confrontational following a year-end party plenary meeting. Kim has since abandoned the country’s decades-long pursuit of peaceful unification with South Korea, designated the South as North Korea’s “principal enemy,” and destroyed a monument to Korean unification located on the outskirts of Pyongyang. These actions reflect the emergence of an escalatory dynamic between the two Koreas following North Korea’s successful satellite launch last November and a shift in the North Korean leadership’s mindset. Domestically, Kim may have concluded that any form of South Korean influence in the North has become so significant a threat to regime cohesion that it is necessary to cut off all potential channels for Seoul’s influence, especially following the regime’s campaign to demonize foreign sway and reject external assistance during the COVID-19 pandemic.

In addition, Kim has sought to take advantage of rising major power rivalry, the renewal of a strategic and military relationship between North Korea and Russia, and the paralysis of the UN Security Council in limiting the prospect of international retaliation for North Korean missile testing. Kim will likely be more militant and aggressive to the extent that he perceives greater room for maneuver as he pursues provocations, especially aimed at South Korea, with relative impunity. Kim’s longstanding strategic objective remains the removal of U.S. forces from the Korean Peninsula and the achievement of a North Korea-led unification of the peninsula.

How has South Korea responded to the latest round of actions and rhetoric from the North?

South Korea has responded primarily with tit-for-tat responses and statements of resolve that raise the perceived cost of military escalation for the North, intended to dissuade North Korea from further provocations. Last month, South Korea retaliated against North Korea’s artillery fire across the Northern Limit Line near Yeonpyeong Island with artillery shelling of its own, both sides signaling their abandonment of the 2018 Comprehensive Military Agreement. South Korea’s President Yoon Suk Yeol has warned against the consequences of North Korea’s continued military testing and has regularly condemned North Korea’s missile launches and expanded collaboration with Russia. On January 31, President Yoon raised concerns that North Korea could pursue a range of unconventional provocations and potential attacks on the South that could be timed to interfere with Seoul’s April 10 National Assembly elections. Yoon’s statements have provided warnings to the North regarding the consequences of direct confrontation and have emphasized that such actions serve only to enhance North Korea’s international isolation.

What is the state of development of North Korea’s most advanced military arms, including ballistic missiles and nuclear warheads?

North Korea has methodically pursued testing and expanded deployment of its nuclear and missile programs as laid out in the five-year plan adopted during the Eighth Party Congress in January 2021. North Korea’s stockpiles of fissile materials have continuously expanded through the operation of uranium-enrichment and plutonium-based reactors at the Yongbyon Nuclear Scientific Research Center, the country’s major nuclear facility.

Current estimates suggest [PDF] that North Korea has sufficient fissile material to deploy around fifty to seventy nuclear weapons. In addition, the range and accuracy of North Korea’s nuclear delivery capabilities have improved, and its inventory has expanded to include both tactical and strategic nuclear weapons and delivery systems. North Korea has also codified its nuclear status and stated it would consider nuclear use as a preemptive response to any perceived threats to the Kim regime.

North Korea’s steady progress includes the testing of smaller and lighter­—as well as larger—nuclear weapons for battlefield use, the development of solid-fuel engine-propelled intercontinental underwater and ground ballistic rockets, the improvement of long-range missiles to 15,000 kilometers capable of striking with “pinpoint accuracy,” the development of hypersonic missiles, the deployment and operation of a military reconnaissance satellite, and the development of a submarine-launched ballistic missile capability. The primary remaining task involves further testing and deploying of a submarine with a long-range nuclear missile launch capability. Speculation also continues to fester over whether North Korea could be planning a seventh nuclear test in the near future.

What’s the status of international sanctions against Pyongyang, including UN Security Council measures enacted in response to its nuclear program?

Almost a dozen UN Security Council resolutions regarding North Korea’s nuclear and missile development remain on the books. But it has been impossible to gain a consensus among the Security Council members on any new punishments for North Korean violations of existing resolutions, primarily due to China’s and Russia’s opposition. The two countries, which have longstanding ties with North Korea, have argued since 2020 that existing sanctions have outlived their purpose; they have not enforced, or have even actively flouted, existing resolutions while managing their respective trade relations with North Korea. In addition, the UN Panel of Experts tasked with monitoring the implementation of existing resolutions has found itself increasingly paralyzed in its ability to investigate and recommend additional enforcement actions. As a consequence, the United States has put greater emphasis on imposing its own unilateral sanctions for North Korean provocations and has worked more closely with like-minded partners, including Japan and South Korea, to coordinate sanctions policies against North Korea.

How extensive is North Korea’s military relationship with Russia? Does it go much beyond the transfer of arms Russia is said to be using against Ukraine?

North Korea’s defense relationship with Russia has steadily expanded in volume and scope since the spring of 2023. Initial reports focused on North Korea’s supply of 152-millimeter caliber munitions to Russia via ship and train for battlefield use in its war in Ukraine. Estimates by South Korea’s National Intelligence Service indicate that North Korea has supplied more than one million shells since August 2023. In early January 2024, the U.S. government also reported Russian battlefield use of North Korean short-range ballistic missiles modeled off of Russian Iskander missiles that North Korea has produced and tested in recent years. The U.S. Department of State sanctioned a Russian air transport wing and related entities on January 11, only weeks after evidence emerged of North Korea-supplied short-range missiles on the battlefield in Ukraine.

In return, there has been speculation that Russia provided technical assistance for North Korea’s successful November 2023 satellite launch, which followed two previous failed launches earlier in the year. North Korea would benefit from Russian provision of military-related technologies to enhance its artillery, aviation, missile, and nuclear capabilities, as well as cash, food, and fuel from Moscow.

The expanding North Korea-Russia military relationship has been accompanied by a steady increase of high-level diplomatic contacts between Pyongyang and Moscow, most notably including Kim Jong Un’s visit to Russia from September 12 to 17 and summit with Russian President Vladimir Putin at the Vostochny Cosmodrome. The North Korean and Russian foreign ministers have subsequently exchanged visits including Foreign Minister Choe Son-hui’s visit to Moscow in January, during which President Putin expressed a willingness to visit Pyongyang later this year.

Should the United States and regional partners ramp up their presence to deter new provocative steps from the North? Are there prospects for any new diplomatic initiative to ease tensions?

Following President Yoon’s April 2023 state visit to Washington for a summit meeting with U.S. President Joe Biden, the United States and South Korea have taken a wide variety of actions that signal the robust level of alliance cooperation. The two countries have closely coordinated in response to not only North Korea but also regional and international security threats. The most notable action regarding North Korea involved the implementation of the Washington Declaration, through which both allies pledged to step up nuclear planning coordination efforts through the newly established Nuclear Consultative Group (NCG). Two NCG meetings have coordinated a range of follow-on activities designed to strengthen deterrence against North Korea’s nuclear development. In addition, U.S. strategic assets have regularly visited South Korea, including the peninsular overflight of strategic bombers and the resumption of U.S. nuclear submarine visits to Busan after an absence of almost four decades.

Moreover, the Camp David summit among the United States, Japan, and South Korea has enabled closer trilateral cooperation on North Korea-related and regional issues, including the integration of a real-time missile tracking and analysis system for North Korean missile tests. The emergence of opposing U.S.-Japan-South Korea and China-North Korea-Russia coalitions around the Korean Peninsula links peninsular confrontation more closely to broader international interests. This heightens the risks of peninsular confrontation. It also diminishes the prospects for effective diplomacy involving North Korea, despite the obvious need for communication to reduce the likelihood of accidental conflict and to effectively manage such a conflict if it arises.