U.S., allies work to deter Korean War II
U.S. Navy and Republic of Korea Navy SEALs shoot at targets during a bilateral training exercise at Silver Strand Training Complex, November 29, 2022.

U.S., allies work to deter Korean War II

As of July 27, the Korean War armistice has held for 70 years – thanks only to the deterrent strength and steely restraint of the U.S.-ROK alliance. The bad news is that North Korea is severely testing that restraint. The good news is that there appears to be a renewed commitment to deterrence in Seoul and Washington.

High stakes and a low bar Let’s start with the bad news, which emanates from North Korea.

With its growing nuclear arsenal, spasms of missile tests and unpredictable leadership, North Korea has put South Korea, Japan and the United States on edge. In 2022, Pyongyang test-fired more than 90 missiles, including 23 on a single day. Pyongyang has fired off dozens more this year, including ICBM launches in April and July.

Recall that Pyongyang has a terrifying vision to turn Seoul into “a sea of fire,” “sink” Japan “into the sea,” and “reduce the U.S. mainland into ashes” – and a nuclear arsenal to make that vision a reality. Indeed, the Stockholm International Peace Research Institute reports that North Korea now has 30 nuclear weapons – five more than it deployed in 2022.

North Korea’s conventional capabilities are almost as terrifying: 1.3 million men under arms, 4,300 tanks, 13,600 artillery pieces and rocket-launch systems, and hundreds of missiles. If war returns to the peninsula, U.S.-ROK forces expect that every third artillery round fired by North Korea will be a chemical weapon. Just 35 miles from the DMZ, Seoul would bear the brunt of the blow. Even a short war, even a conflict contained to the peninsula, even a preemptive strike that gets “most” of Kim’s nuclear, rocket and artillery capabilities would trigger, in former Joint Chiefs Chairman Gen. James Dunford’s estimation, “a loss of life unlike any we have experienced in our lifetimes.”

The toll from the Korean War should give us pause: 38,000 Americans, 103,000 South Koreans, 316,000 North Koreans, 422,000 Chinese and some 2 million civilians killed during three years of conventional warfare. And today, we have the specter of a mushroom cloud hanging over the sequel. The Pentagon projects more than 200,000 U.S.-ROK military casualties in the first 90 days of Korean War II.

All of this explains why the measure of success in Korea for U.S. presidents is simply getting through another day, another year, another term without another war. That’s a low bar, to be sure, but it’s preferable to the alternative.

Words and actions By word and deed, Seoul and Washington are taking the North Korean threat seriously.

“A nuclear attack by North Korea against the United States or its allies and partners is unacceptable, and will result in the end of whatever regime were to take such an action,” President Joe Biden bluntly declared during an April summit with South Korean President Yoon Suk Yeol. A post-summit declaration soberly reaffirmed that “U.S. commitment to extend deterrence to the ROK is backed by the full range of U.S. capabilities, including nuclear.”

The major byproduct of that summit was the establishment of a Nuclear Consultative Group (NCG), which includes U.S. and ROK defense and national-security officials. The NCG elevates South Korea’s role in nuclear deterrence on the peninsula by enhancing information sharing, developing procedures “to enable joint execution and planning for ROK conventional support to U.S. nuclear operations in a contingency,” and establishing a “joint approach to planning for nuclear contingencies.” The NCG held its first meeting in July.

The U.S.-ROK alliance goes much deeper than words and meetings. Unlike some allies, South Korea isn’t free-riding on the back of America’s military. South Korea fields 500,000 active-duty troops, deploys 2,300 tanks and is pouring resources into a fleet of F-35 stealth fighter-bombers. In addition, Seoul is building an aircraft carrier, fortifying and networking its missile defenses, training alongside U.S. and Japanese forces, and investing in deterrence: South Korea is increasing defense spending by 7% annually between 2017 and 2027, while earmarking nearly 3% of GDP for defense.

The United States is doing its part as well. Some 28,500 U.S. troops are deployed in South Korea. U.S. forces are training ROK forces on a U.S.-built THAAD missile-defense system based in the central part of the country. And at Seoul’s request, Washington is conducting “regular” deployments of “strategic assets to the Korean Peninsula,” such as nuclear submarines and aircraft carrier strike groups (CSG). The Nimitz CSG visited South Korea in March of this year. The Reagan CSG made a port of call in South Korea in late 2022. USS Michigan, a nuclear-powered submarine laden with 150 cruise missiles, docked in Korea a few weeks ago – the first such deployment in six years.

“Our commitment to the defense of the ROK remains ironclad,” as Defense Secretary Lloyd Austin observed during a visit to South Korea earlier this year.

Going nuclear One of the reasons Washington has been so forceful – rhetorically and demonstrably – flows from Seoul hinting that it might join the nuclear club.

With North Korea spasmodically firing off missiles and simulating nuclear attacks against its southern neighbor, Yoon matter-of-factly noted in January that South Korea “could acquire our own nuclear weapons, such as deploying tactical nuclear weapons here in South Korea.” It was the first time an ROK president had made such a statement, though a large majority of South Koreans (71%) support fielding an ROK nuclear deterrent.

Controlling and containing nuclear proliferation has been an enduring goal of U.S. statecraft throughout the nuclear age, especially since the Nuclear Non-Proliferation Treaty (NPT) came into force in 1968. But the free world’s failure to prevent North Korea from breaching the NPT in the 1990s badly weakened the NPT. And the free world’s failure in 2014 to defend Ukraine – which gave up its nuclear arsenal in 1994, in exchange for a commitment from Moscow to respect Ukraine’s borders and sovereignty – further hobbled the cause of nuclear non-proliferation. Ukraine serves as an object lesson of the deterrent power of nuclear weapons – and the danger of not having them. From allies such as South Korea to enemies such as Iran, governments around the world are learning that lesson.

Through the establishment of the NCG and the deployment of “strategic assets” to the peninsula, Washington aims to deter North Korea, reassure South Korea and shore up the NPT. But with Pyongyang adding to its nuclear arsenal, testing more rockets and delivering a constant barrage of threats, U.S.-ROK efforts to bolster nuclear deterrence on the peninsula may not be enough. One middle-ground solution that could deter Pyongyang and provide greater reassurance to Seoul is the re-deployment to South Korea of U.S. tactical nuclear weapons. Washington withdrew its tactical nukes from the peninsula in 1991, in a sign of goodwill and confidence-building that led to an agreement between Pyongyang and Seoul to “not test, manufacture, produce, receive, possess, store, deploy or use nuclear weapons.” Pyongyang observed that pact for about 20 months.

Former State Department official Bennett Ramberg argues that in an era of strained defense budgets and rising instability, “reinstallation of nuclear weapons into South Korea … would enhance deterrence” and “reassure the South Korean people.”

Helping hands Shifting back to some good news, South Korea and other free world partners are deepening cooperation on a range of security issues.

New leadership in Seoul and Tokyo has opened the way for closer ROK-Japan cooperation. The two longtime U.S. allies this year resumed their security-dialogue meetings. During meetings with Austin in June, the defense ministers of South Korea and Japan pledged to stand up by the end of the year a system that will allow the three nations to share real-time data on missile launches. Maritime assets from Japan, the ROK and the United States conducted missile-defense exercises this past spring. And a U.S.-Japan-ROK flotilla held antisubmarine drills in late 2022.

With North Korea recklessly and relentlessly conducting missile tests, Japan in February took the head-turning step of purchasing 500 U.S land-based Tomahawk cruise missiles. As the Japanese government explains, the Tomahawks give Japan “the capability to halt ballistic missile attacks within the territory of our adversaries” (code for North Korea and China). Japan’s deployment of Tomahawks also happens to help South Korea by providing a kind of offshore second-strike capability – and giving North Korea something more to worry about.

Beyond the peninsula, South Korea is participating in NATO’s Cyber Defense Center. The United States, Japan, South Korea and Taiwan are forging the Chip4 Alliance to ensure a steady supply of semiconductor microchips to the free world. And South Korea is playing a key part in the free world’s efforts to defend Europe and liberate Ukraine: Seoul is delivering hundreds of main battle tanks, howitzers and rocket systems to Poland, and Seoul has shipped artillery shells to Ukraine via the United States and Poland and, more recently, directly to Ukraine.

In short, South Korea recognizes that there can be no free-riders in the free world – and that it has an opportunity today to give something back to the free world. Indeed, there’s an interesting symmetry on display here. Just as free-world powers from North America and Europe came to South Korea’s assistance when it was under attack in 1950, South Korea is partnering with other free-world powers from North America and Europe to assist a European nation under attack today.