In a dramatic setback highlighting the fragility of diplomacy, North Korea just announced it is tearing up a landmark 2018 agreement with its southern neighbor aimed at reducing border tensions. 

Pyongyang’s provocative launch of a spy satellite earlier this week set off the collapse of the deal, prompting Seoul to retaliate by resuming closer surveillance along the demilitarized zone.

The risk of catastrophic miscalculation has rarely been higher as the rivals revive hostile military steps not seen since before their brief diplomacy interlude just four years ago. 

With tensions now entering an “irreversibly uncontrollable” phase, the cycle of brinkmanship appears poised to endanger the region once more.

Seventy-five years after the Korean War cemented the division of the peninsula, tensions are again reaching a boiling point as North and South Korea abandon precarious peace efforts. 

What went wrong after the high hopes of their 2018 diplomacy?

Tensions have been rising on the Korean peninsula as North Korea makes advances in its nuclear weapons program and questions mount over the viability of past agreements designed to reduce military tensions along the border. 

This comes amid strained relations between the historic rivals after a brief period of diplomacy in 2018 collapsed.

North Korea announced that it is scrapping a package of military confidence-building measures with South Korea that were established in 2018. 

The announcement came after South Korea said it would partially suspend the agreement and resume closer surveillance operations along the demilitarized zone in response to North Korea’s successful launch of its first military spy satellite earlier this week.

The inter-Korean Comprehensive Military Agreement (CMA) was reached in 2018 between North Korean leader Kim Jong Un and then South Korean president Moon Jae-in.

It was meant to reduce military tensions along the border during a period of intense diplomacy between the countries. “The CMA was basically already dead,” said Go Myong-hyun, a senior fellow at the Asan Institute for Policy Studies in Seoul, noting that North Korea had already blown up a liaison office near the border in 2020.

Under the agreement, the two Koreas had pledged to completely cease all hostile acts against each other and instituted confidence-building measures including a ban on military drills close to the border, restricting live-fire exercises, and establishing no-fly zones. They also removed some guard posts and set up a military hotline.

But according to North Korea’s Central Military Commission, “From now on, our army will never be bound by the September 19 North-South Military Agreement. We will immediately restore all military measures that have been halted, we will withdraw the military steps, taken to prevent military tension and conflict in all spheres including ground, sea and air, and deploy more powerful armed forces and new-type military hardware in the region along the military demarcation line” – said a statement in the Rodong Sinmun state newspaper, referring to the border separating the countries since the Korean War ended.

South Korea’s National Intelligence Service briefed lawmakers that North Korea’s satellite, named Malligyong-1, had successfully reached orbit. North Korean state media released images claiming the satellite had captured photos of U.S. military installations in the Pacific.

According to Go Myong-hyun, the 2018 Military Agreement between North and South Korea was essentially nonfunctional well before North Korea’s recent satellite launch.

Tensions had been rising and the agreement under increasing strain, especially following the failure of negotiations in 2019 between Kim Jong Un and then-U.S. President Donald Trump as well as the election of the conservative hardliner Yoon Suk Yeol as South Korea’s president in 2022. 

Myong-hyun implies the CMA was built on a fragile foundation that crumbled rapidly amid changing political circumstances between the historic rivals.

North Korea has warned it will deploy new weapons and stronger armed forces along the heavily fortified border after Seoul claimed Russia helped Pyongyang with its satellite launch. 

South Korean MPs said the launch was probably made possible with Russian assistance after Kim Jong Un discussed his regime’s space ambitions with Vladimir Putin. 

According to South Korean MP Yoo Sang-bum, who was briefed by intelligence officials, North Korea supplied Russia with plans and data related to its first two satellite launch attempts after Kim Jong Un’s summit with Vladimir Putin. Russia then analyzed this information and provided feedback to North Korea. 

Yoo cast doubt on claims that North Korea had achieved a functioning satellite capability at this stage, given typical development timelines. He suggested Pyongyang would need to substantiate its claims by publishing satellite imagery of targets like Guam. 

Yoo also noted increased collaboration between Pyongyang and Moscow, with North Korea reportedly providing ammunition to support Russia’s invasion of Ukraine, although both governments denied formal arms deals.

Experts warned the scrapping of the military agreement could increase the risk of confrontation along the border. “Accidental clashes can escalate into full-blown conflict, including nuclear strikes,” said Moon Chung-in, a professor who helped negotiate the 2018 deal. 

The agreement committed both countries to ending drills near the border and banned live-fire in some areas, while setting up hotlines and removing guard posts.

Moon Chung-in said: “We have every reason to try to reduce risk and tension and instead the south is going in the opposite direction.” If functioning, the spy satellite would improve North Korea’s ability to gather intelligence on South Korea and provide data in any conflict, experts said.

In response to Seoul’s plans to increase surveillance along the DMZ after the satellite launch, North Korea said Thursday it will deploy new military hardware along the heavily fortified border. State media reported North Korea acted after Seoul partially retreated from the 2018 military agreement designed to reduce tensions.

Analysts said the satellite could help North Korea better target opposing forces, prompting Seoul’s reactive move scaling back the agreement signed by Moon Jae-in and Kim Jong Un to reduce the threat of war. 

But any goodwill from that deal has evaporated as Kim failed to get concessions from the U.S. and South Korea in later talks. Kim has since accelerated North Korea’s ballistic missile program, seeking a nuclear deterrent like Washington’s.

In response, the U.S., South Korea and Japan have stepped up military exercises and deployments seen by Pyongyang as threatening. North Korea denounced the U.S. for potential missile sales to Japan and military equipment to South Korea, calling it “a dangerous act” in state media. North Korea said it was “obvious” who the offensive equipment would target.

On Thursday, North Korea’s Defense Ministry said its army will “never be bound” by the agreement, vowing to deploy “more powerful armed forces and new-type military hardware” along the border. It blamed South Korea’s “intentional and provocative moves” for voiding the deal, warning Seoul must “pay dearly” for pushing tensions to an “uncontrollable phase.”

Pyongyang said South Korea will be held “wholly accountable” for any clashes between the Koreas. “The most dangerous situation along the demarcation line has become irreversibly uncontrollable, due to the serious mistake made by the political and military gangsters of the ‘ROK,’” North Korea said, referring to South Korea.

South Korea and the US have few non-military options to slow the North’s nuclear progress, although sanctions have failed to do so despite harming its economy. China’s support for North Korea hinders more forceful diplomacy. This impasse raises the risk of renewed war, whether by intention or mistake.

Fundamentally, the latest tensions highlight that deeply rooted divisions between communist North Korea and capitalist South Korea have persisted for 75 years. Despite some cooperation, both still see the other as the enemy and maintain postures to retaliate harshly in any conflict.

Overcoming this structural hostility will require leaders on both sides charting a delicate course between diplomacy, deterrence, and pragmatic confidence building measures. Unfortunately, current conditions make a major breakthrough unlikely as historical animosity prevails over reconciliation.

The situation will likely remain unstable as long as both Koreas feel threatened. Though disappointing, the failure of limited agreements like the CMA does not preclude bolder steps being considered toward the elusive goal of bringing permanent peace to the peninsula.

The demise of the 2018 Comprehensive Military Agreement reflects the fragile and reversible nature of attempts to bridge the deep divide between North and South Korea. Despite brief diplomatic openings, the underlying security dilemma and competing interests between the rivals persist. 

Absent fundamental regime change, this cycle of engagement, deterioration, and brinkmanship will likely continue. While near-term breakthroughs are improbable, the situation remains volatile and dangerous. 

Creative diplomacy and incremental confidence-building measures are needed to manage tensions during this protracted standoff. But until both Koreas feel secure in their existence, periodic escalations will pose an acute risk of unintended war. 

Escaping this security dilemma will test the skill and political courage of leaders in Seoul, Pyongyang, Washington, Beijing, and beyond. The future course of inter-Korean relations and potential for reconciliation hangs in the balance.