War Game suggests North Korea could survive nukes

"The North Korean regime has shown several scenarios in which it could use nuclear weapons and still survive."

This line appears in the “Guardian Tiger” table-top exercise (TTX) report released by the Atlantic Council, a U.S. think tank, on May 12.

The war game scenario begins with a Chinese invasion of Taiwan that escalates into a broader conflict on the Korean Peninsula. In the simulation, North Korea launches a tactical nuclear strike on a South Korean air base. The U.S. team then faces a critical decision: whether to respond by dropping a tactical nuclear weapon near Kaesong to hold the North accountable. This decision point becomes a major dilemma.

A U.S. nuclear retaliation could trigger a chain of tactical nuclear exchanges. At the same time, China could take advantage of the situation by intensifying its offensive in the Taiwan Strait while U.S. forces are preoccupied on the Korean Peninsula. The worst-case scenario sees Taiwan falling. In other words, the burden of managing two simultaneous theaters could cause the U.S. to hesitate before retaliating against the North.

What makes this exercise especially notable is that it reportedly involved not only the Pentagon but also officials from U.S. Forces Korea. The simulation has generated significant attention in Washington, not only because it was a joint effort between the government and a think tank, but also because it reveals Washington’s sobering view of the strategic challenges posed by concurrent conflicts in Taiwan and South Korea.

The exercise also presents a grim possibility that has long been overlooked: the widely repeated warning that "the end of the Kim Jong Un regime would follow any use of nuclear weapons" may prove to be an empty threat. China, once regarded as a constant factor, could hinder the implementation of America's extended deterrence, including its nuclear umbrella.

As Washington increasingly discusses not only a Chinese invasion of Taiwan but also scenarios such as a blockade or quarantine, one thing is becoming clear: a second Trump administration is likely to focus its Indo-Pacific strategy squarely on countering China. From that perspective, the U.S. military’s push for greater strategic flexibility appears all but inevitable. Despite denials from both Seoul and Washington, the recent debate over a potential withdrawal or regional redeployment of 4,500 U.S. troops aligns closely with the number typically rotated every nine months—suggesting this may not be a coincidence.

Yet amid growing concerns among officials about when and how U.S. President Donald Trump might once again deliver his “security invoice” demanding greater South Korean contributions to defense costs, there seems to be surprisingly little focus on whether the U.S. nuclear umbrella could actually function under the pressure of Chinese intervention.

"It remains unclear whether America's expanding strategic flexibility will result in reduced U.S. troop levels in Korea, renewed demands for greater cost-sharing, or serve as a bargaining chip in a potential 'big deal' between Trump and Kim Jong Un." In this uncertain environment, the South Korean government must focus on strengthening the nuclear umbrella. If U.S. strategic priorities are now firmly centered on China, South Korea must use this shift to seek more concrete guarantees under the nuclear umbrella.

Confidence in the current Nuclear Consultative Group (NCG) framework may be premature. The combined threats from China and North Korea have already emerged as a new type of security challenge that could undermine the traditional extended deterrence model. As the report warns, “In the future, conventional deterrence models may collapse.”