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Why has control over DMZ access become such a point of contention between South Korea and the U.S.?

Published: 02 Jan. 2026, 07:00

SEO JI-EUN
[email protected]

Tourists use binoculars to view North Korea from the Dora Observation Post in the demilitarized zone (DMZ) in Paju, Gyeonggi, on May 25, 2025. [AP/YONHAP]

[EXPLAINER]

The demilitarized zone (DMZ) has become a political flashpoint in Seoul's foreign and security policy — and an unexpected source of tension between South Korea and the United Nations Command (UNC).

A new legislative push by ruling party Democratic Party (DP) lawmakers to grant the South Korean government authority over civilian access to the DMZ for peaceful purposes triggered a rare public rebuke from the UNC, which maintains control over the area under the 1953 Armistice Agreement, which ended the three-year Korean War in a cease-fire.

In a statement Sunday regarding its assessment of the South Korean military’s envisioned border rule revisions, the UNC reaffirmed its "commitment to maintaining the Armistice Agreement," including the military demarcation line (MDL), and to “supporting measures that prevent escalation and promote stability” within the DMZ.

However, the debate over the jurisdiction of the DMZ for nonmilitary access now touches on sovereignty, alliance coordination and the legal boundaries of the armistice regime — and analysts warn it could influence the future of inter-Korean engagement and even the credibility of the South Korea-U.S. security framework.

South Korean soldiers stand guard at the Joint Security Area (JSA) in Panmunjom, inside the DMZ, during a tour on July 19, 2022. The JSA, with its iconic blue huts (South Korean side) and the grey Panmun-gak building (North Korean side in the background), is one of the few spots in the DMZ where troops from both Koreas face each other directly under the armistice agreement. [JOONGANG ILBO]

Who controls the DMZ, and why does it matter?

The DMZ is a 4-kilometer-wide buffer zone across the Korean Peninsula established by the 1953 Korean War armistice to separate North and South Korean forces.

Although it lies within South Korean territory, all access is controlled by the UNC — the entity through which 18 nations, including the United States and many of the original Korean War combatants — led by Washington.

The armistice’s Article I states that “civil administration and relief activities in the DMZ which is south of the MDL shall be the responsibility of the Commander-in-Chief, United Nations Command,” and no military or civilian personnel may enter the DMZ without specific approval.

Entry requires approval from the UNC’s Military Armistice Commission with 48 hours' notice, a rule not explicitly written into the armistice but enforced for decades. The control extends even to South Korea’s highest-ranking officials, including the president.

The UNC defends its authority as essential to preventing provocations and preserving the armistice’s stability.

They point out that the armistice is a legally binding international agreement aimed at halting all armed conflict “until a final peaceful settlement is achieved,” which includes tightly regulating movement in the DMZ. The UNC has administered the DMZ for over 70 years and credits this regime with helping maintain stability even during periods of high inter-Korean tension.

The agreement is still regarded as a binding international treaty under South Korea’s Constitution. From this perspective, the DMZ is not just Korean territory but also a globally monitored cease-fire zone.

South Korean soldiers salute as the flag-draped remains of a soldier killed in the Korean War (1950-53) are carried from the Baekma-Goji excavation site inside the DMZ on Dec. 1, 2025. Over a 40-day excavation, the military recovered 25 sets of remains and nearly 2,000 artifacts from this former battlefield in Cheorwon, Gangwon, part of efforts to transform the DMZ into a zone of peace. A senior national security official’s visit here was recently blocked by the UNC, sparking controversy. [MINISTRY OF NATIONAL DEFENSE]

How did it all start?

Kim Hyun-jong, the first deputy director of South Korea’s presidential National Security Office, attempted to visit the Korean War remains excavation site at Baekma-Goji, or White Horse Hill, inside the DMZ.

The excavation, managed by the Defense Ministry, took place on the central front of the DMZ from Oct. 15 to Nov. 28 of last year.

Kim’s scheduled visit to the site, however, was denied by the UNC, only to be later publicly revealed by South Korea’s Unification Minister Chung Dong-young. Chung expressed outrage that even a top national security official could be barred from “our own land” in the DMZ.

The incident was framed domestically as a sovereignty issue, since Kim’s role is to oversee national security, and yet he was prevented from visiting a site on South Korean territory.

The UNC did not cite a specific incident or hazard as the reason for blocking Kim’s visit.

Instead, it issued only a general statement of policy, reiterating that as the enforcer of the armistice, it reviews all DMZ access requests according to established procedures to ensure safety and compliance.

Following public criticism and debate, the UNC reversed its stance and allowed Kim to enter the DMZ about two weeks later, on Dec. 17, where it announced via its website and social media that it had granted Kim access to the DMZ.

Unification Minister Chung Dong-young speaks during a joint ministry policy briefing on Dec. 19, 2025. Chung has criticized the UNC denying senior government official's access to the DMZ. [YONHAP]

What would the proposed DMZ law change?

Reps. Lee Jae-gang and Han Jeoung-ae from the DP proposed an act on the peaceful use of the DMZ, or simply "DMZ law," in August of last year.

Although the drafts vary slightly, their core premise is to allow the South Korean government — specifically the Unification Ministry or other agencies — to independently approve civilian access to the DMZ for nonmilitary and peaceful purposes, bypassing UNC control.

One version explicitly states that the Unification Minister can authorize DMZ access “notwithstanding the Armistice Agreement,” after review by a special committee.

Another version similarly empowers a government committee to grant DMZ entry permits by presidential decree. The legislation also proposes that this new DMZ law would take precedence over any conflicting domestic laws, such as existing border area or military facilities protection laws.

Advocates argue that the UNC’s blanket control is overly restrictive and has impeded harmless civilian endeavors in the past.

South Korean National Assembly Speaker Woo Won-shik, right, and Roman Catholic Cardinal Lazzaro You Heung-sik place postcards in a mailbox at the Imjingak Peace Park in Paju, Gyeonggi, on July 23, 2025, to express hopes for inter-Korean reconciliation. A planned prayer ceremony by the visiting cardinal near the DMZ was canceled in 2025 due to procedural hurdles with the UNC’s 48-hour approval rule. [JOINT PRESS CORPS]

Before the deputy national security adviser's denial, a prayer-for-peace ceremony by visiting Cardinal Lazzaro You Heung-sik was also canceled for procedural reasons. The UNC cited that the cardinal’s team requested access on short notice, not adhering to the standard advance notification timeline.

During the inter-Korean summit in 2007, then-President Roh Moo-hyun had to receive final clearance from the UNC’s operations center before crossing the MDL in front of live cameras.

Yang Moo-jin, a distinguished professor at the University of North Korean Studies, argues that while the armistice grants the UNC access control, that authority should apply strictly to military matters.

“The UNC’s role should be limited to military functions under the armistice,” Yang told the Korean press.

Yang pointed specifically to the Kim case, only to be later granted access after public criticism, shows an "overextension" and "arbitrary interpretation" of its mandate.

“This shows that the UNC is reacting politically, not legally — which it was never meant to do,” he said.

Gen. Xavier Brunson, commander of United States Forces Korea, delivers a commemorative speech during a ceremony to celebrate the UN Forces Participation Day at Kintex in Goyang, Gyeonggi, on July 27, 2025. [JOING PRESS CORPS]

Why are the UNC and others opposed to it?

The UNC issued an unusual public statement on Dec. 17 strongly opposing the bill.

In it, the command reiterated that DMZ access control “is the inherent authority of the UNC under the armistice,” quoting the agreement’s clause that no personnel may enter without MAC approval.

UNC officials warn that if South Korea passes a law to unilaterally override those armistice provisions, it would amount to a breach of an international agreement.

The UNC commander Gen. Xavier Brunson, who also heads U.S. Forces Korea, stressed that the command’s actions are governed by the Korean War armistice, and "we've got to adhere to the standards put forward" in the agreement.

He cautioned that the UNC cannot "seek to change the way we do business in abrogation of a legal document, which is the armistice.”

The South Korean Ministry of National Defense echoed the UNC's position.

In an official review submitted to the National Assembly, the ministry acknowledged the “intent” of enabling peaceful DMZ use but insisted that any steps must be done in close coordination with the UNC.

South Korea's conservative camp, including the opposition People Power Party (PPP), went further, saying undermining UNC authority would “remove the basis for UN member states’ automatic intervention” in a crisis, essentially weakening a key “safety pin” for South Korea’s security.

“Attempting to nullify an international pact [the armistice] through domestic law is a blatant violation of the Vienna Convention,” said PPP spokesman Park Sung-hoon, calling it an act that could turn South Korea into an international “rogue state” that breaks its commitments.

Will the DMZ law strain the alliance?

The DMZ law debate ultimately reflects a deeper tension — South Korea’s ambition for greater autonomy versus the practical constraints of a 70-year-old armistice system.

Washington has allowed the UNC to lead the response so far, but this isn't the first time the two sides have faced strain.

During the inter-Korean detente in 2018, the United States, through the UNC, slowed some inter-Korean projects that were moving faster than U.S.-North Korea talks.

The UNC exercised control over DMZ access and delayed or restricted some inter-Korean projects, such as the joint railway survey in the DMZ and some military de-escalation measures or site visits under a comprehensive military agreement signed by the two Koreas that year.

South Korea, rather than act unilaterally or override UNC authority, adjusted its timelines and coordinated with Washington.

Today, the PPP called the DMZ bill a dangerous move that could erode tight South Korea-U.S. cooperation on North Korea policy.

“Shaking the UNC’s authority is a very dangerous idea that weakens the framework of our alliance,” said Park, adding that it amounts to “security self-harm.”

This is exactly what North Korea desires, PPP officials note, adding that Pyongyang has long demanded the dissolution of the UNC, viewing it as a U.S.-led mechanism to bring multinational forces against the North.

North Korean state media denounced the recent revitalization of UNC activities as a “second, Asian version of NATO" on the peninsula in a Foreign Ministry statement carried by state media Korean Central News Agency in August 2024.

Still, the unification minister reiterated his support for the DMZ law in a joint policy briefing on Dec. 19, citing the recent incidents of denied entry.

"That is our reality," he said, stressing the need for legal authority to guarantee peaceful access.

BY SEO JI-EUN [[email protected]]