Editor's Note

Lieutenant General In-bum Chun (ROK, Ret.) examines North Korea’s coastal defense capabilities in the West Sea and analyzes how its ongoing military modernization and territorial claims exacerbate security tensions on the Korean Peninsula. He points out that countering North Korean coastal threats necessitates careful political decision-making, as any military action could lead to escalation. In this context, Chun stresses that negotiation, rather than conflict, is the essential path to stability.

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Kim Jong Un declared in January 2024 that North Korea would no longer seek peaceful unification with South Korea, effectively abandoning decades-long goal of reunification based on national homogeneity. This announcement, made during a session of the Supreme People’s Assembly, also included a call for a constitutional change labeling South Korea as the “primary foe” (Korean Central News Agency [KCNA] 1/16/2024). This policy shift reflects a significant hardening of North Korea’s stance, aligning with Kim’s strategy of bolstering military capabilities and reducing diplomatic engagements.


At first glance, it seemed as if North Korea was resigned to a status quo of two Koreas on the Korean Peninsula and, with nuclear weapons to protect them from external threats, was going to focus on internal stability and economic improvements for its people. However, following the initial announcement, North Korea swiftly erased all notions of peaceful unification by changing station names, altering song lyrics, and demolishing monuments related to the goal of unification. North Korea continues with missile developments, attempted satellite launches, and a possible nuclear test.


Recently, Kim Jong Un has made several provocative statements regarding the Northern Limit Line (NLL), the so called “disputed” maritime border between North and South Korea. During a test-firing of a new surface-to-sea missile, Kim ordered a strengthened defense posture near the NLL, which he described as “a ghost one without any ground in the light of international law or legal justification” (KCNA 2/15/2024). He emphasized that North Korea does not recognize the NLL and warned that any incursion by South Korean vessels would be considered an act of war. In the same speech at the Supreme People’s Assembly in January 2024, Kim reiterated his stance, stating that the “illegal northern limit line and any other boundary can never be tolerated” (KCNA 1/16/2024). He warned that even a minimal violation of North Korean territorial waters would be seen as a provocation and a casus belli, potentially leading to armed conflict.


I. Historical Background


When the armistice agreement was signed, all islands surrounding the Korean Peninsula were under the control of the United Nation (UN) Forces. The Korean War Armistice Agreement, signed on July 27, 1953, includes specific provisions regarding these islands. The agreement stated that certain coastal islands occupied by one side but controlled by the other side as of June 24, 1950, would be addressed. It stipulated that islands north and west of the provincial boundary between Hwanghae-do and Gyeonggi-do would fall under the military control of the North Korean People’s Army and the Chinese People’s Volunteers, except for five island groups (Baengnyeongdo, Daecheongdo, Socheongdo, Yeonpyeongdo, and Udo), which would remain under the control of the United Nations Command (UNC).


Many of the islands north of the boundary between Hwanghae-do and Gyeonggi-do were controlled by UN forces, mainly guerilla and commando units comprised of anti-communist North Koreans. These islands served as bases for infiltrating North Korean rear areas to conduct special operations and rescue missions for downed UN pilots. When the agreement was signed, many of these men and women were forced to give up control of the islands they had defended with their lives and at great sacrifice.


North Korea began to lay formal claims to the northwest island area, including the Five West Sea Islands, in 1973. This was when North Korea made a claim to extend its territorial waters to 12 nautical miles, which included these islands administered by South Korea but located closer to the North Korean mainland. This claim challenged the NLL, which was established unilaterally by the United Nations Command (UNC) in 1953 following the Korean War to demarcate the maritime boundary between the two Koreas.


The NLL was intended to prevent accidental naval clashes, but North Korea has never recognized this boundary and has frequently contested it. In 1999, North Korea further escalated its claims by declaring its own maritime border, known as the “West Sea Military Demarcation Line,” which overlaps with the NLL and excludes the disputed islands. This ongoing “dispute” has led to numerous military clashes over the years, including the sinking of a South Korean naval vessel in 2010 and artillery shelling of Yeonpyeong Island later that same year.


II. North Korean Military Capabilities in the Northwest Islands


It is estimated that North Korea has close to two hundred coastal artillery pieces aimed at the NLL and within range. Although these are medium caliber artillery guns, they are fortified in caves and bunkers, making them hard to destroy with conventional ship guns. These fixed positions have an advantage in a gunnery duel with ships that must shoot afloat. Additionally, North Korea has Surface to Ship Silkworm missiles that have a range of 100 km and a sizable warhead. The Silkwarm missile is significant in naval warfare, particularly in coastal defense roles, due to its effectiveness in targeting surface ships. Recently, North Korea has been test launching the Padasuri (바다수리), or Sea Eagle.


The Padasuri-6 missile is a newly developed surface-to-sea missile by North Korea, prominently mentioned in recent military reports. It was recently tested under the supervision of North Korean leader Kim Jong Un. The test was reported on February 15, 2024, by KCNA. The missile flew for approximately 23 minutes over the East Sea and successfully hit a target boat. The Padasuri -6 is modeled after the Russian Kh-35 Uran cruise missile, indicating that it is a subsonic anti-ship missile with a potential range of over 100 km. It is intended to enhance North Korea’s coastal defense capabilities and is likely equipped with improved guidance systems for targeting South Korean ships that patrol the NLL.


The missile test was part of North Korea’s broader strategy to bolster its military presence and readiness around disputed maritime areas, particularly near the NLL. Kim Jong Un has emphasized the importance of maintaining military preparedness in the waters north of South Korea’s Yeonpyeong and Baengnyeong islands, where he claims South Korean warships frequently encroach. The development and testing of the Padasuri-6 missile come amidst heightened tensions between North and South Korea, with Kim Jong Un reiterating North Korea’s refusal to recognize the NLL and threatening to consider any violation of its claimed maritime boundaries as an act of war. These developments reflect North Korea’s continued efforts to modernize its military arsenal and assert its territorial claims in the region, further complicating the security dynamics on the Korean Peninsula.


In addition to the threat to shipping in the Northwest islands, the North Korean military has the capability to mass fires against the islands as well as attempt amphibious landings with hovercraft. Although this will be a costly operation for any military force, it is within the realm of possibility and probability that the North Koreans have been preparing for.


III. Countering the Military Threat in the Northwest Islands


Military vessels are armed with anti-ship defense measures, but a barrage of missiles fired at one target will always be a challenge to defend. Therefore, to counter North Korean coastal threats, the most effective strategy is to neutralize their coastal guns and missile sites before they launch. However, this requires careful political decision-making. Detecting North Korean radar targeting our ships would necessitate either halting naval operations or risking our sailors’ safety. Preemptive airstrikes to destroy radar sites could escalate the conflict, activating North Korean air defenses and anti-aircraft missiles. Consequently, the best option is negotiation. Political leaders must balance military readiness with diplomatic efforts to avoid escalation.


For these North Korean guns or missiles to be effective, they must target our ships with radar. When North Korean radar sites start targeting our ships, we would have to either cease naval operations or put our sailors in danger. The other alternative is to destroy these radar sites with air power. Fighter aircraft launched from aircraft carriers or land bases would be deployed to take out these radar sites. The North Koreans, of course, would activate their air defenses and launch their anti-aircraft missiles at our aircraft. Due to this threat, we would have to target and destroy these anti-aircraft radar sites before attempting to destroy the anti-ship radar sites. The unfortunate conclusion is that escalation would be unavoidable.


The best option is not to fight but to negotiate. This is the realm of political leaders. The military option should be one of many available to political leaders. North Korea must understand that South Korea is capable and determined to defend itself, while South Korea must recognize the potential costs of conflict. A negotiated settlement remains the best path to avoid escalation and maintain regional stability.




Korean Central News Agency (KCNA). 2024. “Respected Comrade Kim Jong Un Makes Policy Speech at 10th Session of 14th SPA.” January 16. http://kcna.co.jp/item/2024/202401/news16/20240116-02ee.html


________. 2024. “Respected Comrade Kim Jong Un Guides Test-fire of Surface-to-sea Missile Padasuri-6.” February 15. http://www.kcna.kp/en/article/q/2866630de1847cb23e4c8b38b53dfcb7.kcmsf



Lieutenant General In-bum CHUN (ROK, Ret.) served 38 years in the South Korean Army and retired in 2016. He is currently a Senior Fellow with the Association of the United States Army.



Typeset by: Jisoo Park, Research Associate
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