Ukraine Symposium – North Korea’s Entry into International Armed Conflict

In recent months, the world has observed the methodical introduction of the Democratic People’s Republic of Korea (DPRK) into the ongoing Russia-Ukraine international armed conflict (IAC).

On June 19, 2024, President Vladimir Putin met with North Korean leader, Kim Jong Un, to sign a mutual defense treaty, laying the  foundation for future mutual assistance in armed conflict. On October 18, 2024, reports emerged that over 12,000 DPRK troops had deployed to Russian soil to engage in training exercises. Shortly thereafter, Western media published videos depicting Russian personnel issuing military uniforms to North Korean soldiers.

At the time, Ukrainian President Volodymyr Zelenskyy expressed his concern about DPRK troops entering the conflict by posting a video to Telegram stating, “Ukraine will be forced to defend themselves against them, and the world will watch again. … Everyone in the world who truly wants the Russian war against Ukraine not to expand … must not just watch. They must act … .”

Despite Zelenskyy’s plea, North Korean and Ukrainian troops engaged in combat for the first time in the Kursk region of Russia on November 4, 2024.

This post tackles conflict classification, an essential step in any international humanitarian law (IHL) analysis by examining whether an IAC exists between Ukraine and DPRK, and if so, when it precisely began. We conclude that an IAC between DPRK and Ukraine does exist, and most likely began on October 23, 2024. This was the date of mass DPRK force movement to the Forward Line of Own Troops (FLOT).

International Armed Conflict

Article 2(1) of the four 1949 Geneva Conventions (GCs) states that IHL applies to “all cases of declared war or of any other armed conflict which may arise between two or more High Contracting Parties, even if the state of war is not recognized by one of them.” In the seminal Tadić decision, the International Criminal Tribunal for the former Yugoslavia (ICTY) defined “armed conflict” as existing “whenever there is a resort to armed force between States …” (para. 70). The Tadić tribunal’s use of the word “between” recognizes the existence of a belligerent relationship between parties, including the unilateral use of force by one State against another.

The International Committee of the Red Cross (ICRC) affirms there is no specific intensity threshold for finding that an IAC exists. The ICRC also notes that even minor skirmishes between armed forces, by land, sea, or air could trigger an IAC. In short, the test for whether an IAC exists is de facto and thus objectively assessed based on the totality of the circumstances.

Based on the above standards, an IAC had certainly ripened between the DPRK and Ukraine as of the November 4, 2024 combat engagement. Despite a Ukrainian official’s characterization of “small contacts, not full-scale engagement,” the circumstances nonetheless support the conclusion that an IAC exists. Ukraine reported that an estimated 11,000 North Korean soldiers were in the Kursk border region. The DPRK troops were armed, wearing Russian uniforms, and maneuvering under the command of Russian forces near Ukrainian positions. These factual circumstances foretell impending engagements involving a significant number of DPRK forces. While the cessation of an IAC is beyond the scope of this post, we offer that the IAC will remain in effect until the factual circumstances change (i.e., the cessation of DPRK military operations and hostile actions toward Ukraine).

A more interesting question concerns when precisely the IAC began. Beyond an academic exercise, establishing a specific initiation date is practically important and legally significant. Once an IAC is in effect, IHL controls as lex specialis. For instance, if the IAC began earlier than November 4, 2024, Ukrainian forces could have lawfully attacked DPRK forces as a first resort. More likely, if allegations emerge that some adversarial action (e.g., an offensive cyber operation) was taken by Ukrainian or DPRK forces against the other prior to the November 4, 2024 engagement, assessing its legality first requires establishing whether IHL applied at the time.

We therefore analyze the legal strength of arguments that the DPRK-Ukraine IAC began at the following points in time: (1) when DPRK provided material support (munitions) to Russia; (2) when DPRK signed the mutual defense agreement; (3) when DPRK forces deployed to Russian soil; (4) when Russian forces trained and equipped DPRK forces with Russian weapons; and (5) when DPRK troops moved to the FLOT in Russia’s Kursk Region.

Prior to considering these questions, however, we must briefly address the status of the DPRK forces in Russia. More specifically, we must assess whether DPRK troops in Russia should be considered something other than DPRK forces for the purpose of conflict classification.

The Status of DPRK Forces in Russia

The law should regard DPRK forces as their own independent armed force for the purposes of assessing belligerency and conflict classification, rather than as militias or volunteer corps forming part of the Russian armed forces as understood under Article 4A(1) of GC III. The 2020 ICRC Commentary on GC III notes that a militia or volunteer corps must satisfy two prongs to fall within subparagraph 4A(1) and thereby qualify for prisoner of war status. First, the militia or volunteer corps must have been formally incorporated into the armed forces prior to its members falling into enemy hands. Second, it must fall under the responsible command of a party to the conflict.

The manner of incorporation is a question of domestic law. While some reports suggest DPRK soldiers are operating under the command of Russian forces, Marko Milanovic aptly observes the uncertainty pertaining to command relationships and the question of whether Russia has a sufficient number of officers and interpreters to command DPRK troops. Thus, the second “responsible command” prong remains unclear.

Further, there is no indication of a wider effort to formally incorporate DPRK forces into the Russian military command structure. DPRK forces are in Russia because of official coordination between Russian and DPRK leadership. It is likely DPRK forces will remain under Russian command until their role in active combat operations increases. This may include freeing up Russian forces to support the slow-moving offensive in the eastern Ukrainian oblasts. Accordingly, because DPRK forces fail to satisfy the two-pronged test, they do not amount to a “militia or volunteer corps” forming part of the Russian armed forces.

Additionally, DPRK forces are not mercenaries as provided for under Article 47 of Additional Protocol I to the Geneva Conventions (AP I), an instrument to which the DPRK is a State party. There are 6 cumulative conditions that must be satisfied for one to constitute a mercenary: 1) recruited locally or abroad to fight in an armed conflict; 2) directly parties in hostilities; 3) motivated by private gain; 4) is neither a national of a Party to the conflict nor a resident of territory controlled by a Party to the conflict; 5) is not a member of the armed forces of a Party to a conflict; and 6) is not sent on official duty to an armed conflict as part of the of the armed forces of a State not Party to the conflict.  Here, the sixth condition is most pertinent. All reports, including senior level Russian and DPRK government statements, affirms that the members of the DPRK military, including elements of its special forces, were on official duty status while assisting Russia in its ongoing combat operations.  Thus, DPRK forces are not “mercenaries,” but rather members of a State’s armed forces, engaging in armed conflict with Ukraine.

Law of Neutrality  

Next, we apply neutrality law. Traditionally, States are either belligerents or neutral. Neutral States must remain impartial and are obligated to refrain from providing war-related goods and services to belligerents. Neutral lands, water, and airspace can neither be used as a base of belligerent operations nor transited (Department of Defense (DoD) Law of War Manual §§ 15.13.1, 15.5).

The DoD Law of War Manual references an approach predating the Second World War termed “qualified neutrality,” which provides for the right of neutral States to support States that are victim to flagrant and illegal wars of aggression. Article 2(5) of the UN Charter may supersede neutrality rules based on a UN Security Council request for assistance. Finally, the United States argues qualified neutrality applies when violating any impartiality required by regional and collective self-defense arrangements.

In the case of Ukraine, the United States applies the qualified neutrality view to support Ukraine by supplying military aid because Russia, through its act of aggression, violated Ukrainian sovereignty. State practice through arms exports in support of Ukraine demonstrate a deviation from the strict rules of neutrality. However, as Professor Hitoshi Nasu noted, many States remain apprehensive to the application of qualified neutrality. Even if qualified neutrality was considered customary international law, DPRK—or any other State that provides material support to Russia—violates international law because Russia initiated an act of aggression against Ukraine. The DPRK and other States are precluded from relying upon qualified neutrality to further Russia’s internationally wrongful act as extensively discussed by Professor Michael Schmitt in his post.

The Transition from Neutral to Belligerent

A State’s neutrality ends in one of three ways: (1) when the neutral State enters an IAC as a belligerent; (2) when a belligerent attacks the neutral State; or (3) when a belligerent declares an IAC exists between itself and the neutral State. This post focuses on the first criterion, namely when the DPRK entered the IAC with Ukraine as a belligerent.

As the U.S. DoD Law of War Manual notes, “[a]cts that are incompatible with the relationship between the neutral State and a belligerent State under the law of neutrality need not end the neutral’s State’s neutrality and bring that State into conflict as a belligerent” (§ 15.4.1.). Instead, the breach of neutrality law amounts to an internationally wrongful act, entitling the victim State to take non-forcible countermeasures in response. While there is a point when a formally neutral State’s support to a belligerent “crosses the Rubicon” and changes the State’s status from neutral to belligerent, the exact degree and extent of support necessary to trigger a status change remains unsettled.

The ICRC’s informative assessment in the context of non-international armed conflicts (NIAC) may help in analyzing whether any given foreign intervention makes a formally neutral intervenor a party to a conflict. According to the ICRC, a third-party State becomes a party to a NIAC under the following conditions: (1) a preexisting NIAC exists in the territory where the third power intervenes; (2) the intervening power takes hostile actions in the context of the pre-existing conflict; (3) the intervening power’s military operations support one of the parties to the pre-existing NIAC; and (4) the intervening power makes an official decision to support a party involved in the preexisting conflict. Examples of acts that can make States a party to a NIAC include logistical support involving the transportation of troops, the provision of intelligence used immediately in the conduct of hostilities, and the involvement of State officials in planning and coordinating one of the belligerent’s military operations.

This framework highlights that a State’s actions to further the interests of a belligerent power may lead it to become a party to the conflict. Professor Schmitt provides an additional analytical framework, noting practitioners should assess whether the State’s behavior crosses the conflict initiation threshold by engaging in hostile acts or military operations. As Professor Schmitt notes, it is not a State’s violation of its duties under the law of neutrality that makes it a party to an IAC, but rather a State’s underlying actions, such as conducting attacks on behalf of a belligerent.

We now turn to the different stages of the DPRK’s involvement in the Russia-Ukraine war to determine whether they led North Korea to become a party to the existing IAC.

DPRK’s Provision of Material Support

Under the IHL regime, the DPRK’s supply of war material to Russia does not by itself make it a party to the IAC with Ukraine. As Professor Schmitt noted, the analysis should assess the underlying actions of the State rather than the strict violation of neutrality. State practice suggests that arms transfers are not, by themselves, acts that make a State party to an IAC. Supplying military aid does not rise to the level of direct participation in hostilities or mean the DPRK is a co-belligerent.

In Tadić, the court opined that equipping and financing a non-State group does not by itself internationalize a NIAC (para. 131). If material assistance to a non-State group in a NIAC does not initiate an IAC between the supporting State and the State against which the arms and equipment would be employed, it is insufficient to establish co-belligerency (see Schmitt, here). Such material support does not involve taking part in, planning, or supervising military operations that rises to the level of co-belligerency.

It is beyond the scope of this post to address the separate but connected jus ad bellum issue of whether DPRK material support to Russia could constitute a prohibited use of force (see Schmitt and Biggerstaff). It is, however, important to note that although material support alone does not make the DPRK a party to an IAC, this conduct could engage the DPRK’s international responsibility based on the rules reflected in Articles 16 and 41(2) of the Articles on State Responsibility for its complicity in Russia’s acts of aggression against Ukraine.

DPRK’s Mutual Defense Treaty with Russia

The June 2024 mutual defense agreement between Russia and the DPRK does not, by itself, make the DPRK a party to an IAC. Although bilateral defense-related treaties may set the conditions for an allied State to join an IAC, they do not necessarily require the allied State to breach its neutrality obligations in favor of satisfying treaty obligations. This post does not address the inherent tension between neutrality and bilateral defense-related treaty obligations.

Russia and the DPRK entered their mutual defense agreement after the initiation of hostilities in Ukraine. They may have done so with the express intention that DPRK military forces would become directly involved in the conflict under a legal pretext of mutual assistance. However, at the time of the treaty’s signing, the extent of the DPRK’s participation in the Ukrainian IAC remained unknown and speculative. As a caveat, we note the DPRK subsequently ratified the defense treaty on November 11, 2024, approximately one week after the combat engagement on November 4, 2024

DPRK’s Arrival and Training on Belligerent Soil

To determine when the IAC between the DPRK and Ukraine commenced, it is necessary to distinguish between the deployment of forces exclusively for training purposes and deployments intended for future operations in support of a belligerent power in an ongoing armed conflict. White House national security spokesman John Kirby captured this distinction when commenting on the October 23, 2024, deployment. He said, “[t]hese Soldiers then traveled onward to multiple Russian military training sites in eastern Russia, where they are currently undergoing training. We do not yet know whether these Soldiers will enter into combat alongside the Russian military… .” Secretary of Defense Lloyd Austin added, “[i]f they’re co-belligerents, their intention is to participate on Russia’s behalf, that is a very, very serious issue… .”

The mere arrival of North Korean soldiers on Russian territory does not by itself create an IAC between the DPRK and Ukraine. However, given the arrival of a significant number of DPRK forces following the June mutual defense treaty, it is reasonable to conclude that the DPRK forces were there to enter combat. Additional intelligence indicators may support this conclusion, including factors such as the purpose and intent of the deployment, where the deployed force is in proximity to the conflict zone, the duration of the deployment, and the levels of coordination and communication between senior political, military, and intelligence components of the belligerent and neutral State.

In the case of the DPRK, between 10,000 and 12,000 North Korean troops—including 500 officers and three DPRK generals—were reportedly training in Russia, spread across five military bases. Intelligence reports increasingly suggest DPRK forces are operating in proximity to active combat zones in Russia and Ukraine. Additionally, through artificial intelligence facial recognition technology, South Korea identified DPRK forces visiting frontline areas in Ukraine, purportedly giving Russian forces guidance on DPRK-made KN-23 ballistic missiles.

Reports also indicate that Russians have been training DPRK forces on Russian-specific military doctrine and practice. Such training—on Russian soil—reportedly includes teaching Russian commands and instruction on the use of Russian weapon systems. Russia’s decision to train and equip DPRK forces constitutes a significant step toward and integral part of coordinated military operations that set the conditions for future rapid deployment to active combat zones in Ukraine. Moreover, the logistical requirements to transport, house, and train thousands of forces require enhanced coordination and planning between the DPRK and Russian military commands. Although identifying a specific date for this development remains elusive via open-source information, it nonetheless stands as a decisive turning point in the war.

Based on these reports, it is reasonable to conclude that the DPRK sent its troops to Russia intending to participate in future operations involving active hostilities against Ukraine, rather than merely participating in ancillary training exercises. Based on the totality of the circumstances, it is reasonable to contend that an IAC existed between Ukraine and the DPRK as early as the initial mid-October deployments.

Mass Transport of DPRK Troops

The deployment of thousands of DPRK forces to the front lines of the battlefields in Russia and Ukraine in late October is the clearest indicator that an IAC exists between the DPRK and Ukraine. Open-source reports place DPRK troops on the front line on October 23, 2024. In staging its troops at the front lines, the DPRK quelled any lingering notion that its forces were merely there in an observer/trainer capacity. Ukraine could therefore reasonably conclude the DPRK intended to join the conflict.

The DPRK’s act of deploying thousands of forces towards an active combat zone on Russian logistic networks constitutes a threat of an imminent attack. It follows that Russian troop transports could have been lawful targets had Ukraine elected or had the means to target them en route.

Conclusion

An IAC exists between the DPRK and Ukraine. While some may point to the first armed engagement on November 4, 2024, as the official date on which the IAC commenced, we suggest that an IAC conceivably existed on or around October 15, 2024, when DPRK troops arrived on Russian soil. Although, we are more firm in offering that the DPRK-Ukraine commenced on October 23, 2024, when armed, uniformed, and trained DPRK forces took positions on the front line, ready and standing by to receive Russian military orders.

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Lieutenant Colonel Steve Szymanski is an active duty Army judge advocate, currently assigned as a Fellow and Instructor at the International Institute of Humanitarian Law (IIHL) in Sanremo, Italy.

Captain Joshua C.T. Keruski is an active duty Army Judge advocate currently assigned as a National Security Law Attorney at United States Army Counterintelligence Command in Fort Meade, Maryland.

Photo credit: Roman Harak