From your perspective as a former Commander of the UN Command in the Republic of Korea, what are the biggest challenges today in aligning US and South Korean strategic priorities, especially on issues related to extended deterrence or responses to North Korean aggression?

The biggest challenge is generating the right degree of trust. I have confidence in the Korea–U.S. alliance—it is a strong alliance that has withstood pressure from both outside and inside the relationship over the decades. But there has to be a clear understanding of what each country needs and how each country views extended deterrence, and that is where trust concerns emerge.

For example, in South Korea there is a recurring question: will the United States, in fact, protect us with this nuclear umbrella? It says that it will, but how do we know? That limited doubt can drive South Korean program development to compensate for the possibility that the U.S. might not provide support. Meanwhile, the United States says: the support is already provided; the umbrella covers you every day. It exists all the time—not just sometimes—and one of its purposes is the protection of South Korea on the Korean Peninsula.

So, building confidence is the core challenge. There are also cultural differences in how problems should be addressed. When you put trust and culture together, those are the central issues in aligning priorities.

You have argued that the quality of US foreign policy depends on the quality of our understanding of each other. What are the most common misconceptions the US holds about its allies in the Indo-Pacific region? What are some prevailing assumptions in US–Indo-Pacific policy that you believe need rethinking?

In my experience, the United States sometimes expects that other countries see the problem the same way we do and, with that, expects partners—South Korea, Japan, the Philippines, Malaysia, take your pick—to fall in line with U.S. thinking. That can overlook how those countries actually see the problem and why they may balance relations with China differently from the United States.

A good illustration is the South Korea–Japan relationship. For years, the U.S. has said, “There is no reason you shouldn’t be cooperating, given the common threats you face—especially from North Korea. Why aren’t you working together? It isn’t that hard.” That ignores some of the underlying cultural and societal challenges to cooperation between Japan and South Korea, which are more difficult for the United States to understand. And so, sometimes these assumptions make it very difficult for countries to choose what is consistent with their interests as they see them, to make sovereign decisions regarding that, and, at the same time, to maintain their relationship with the United States.

Given the growing strategic competition between the US and China, how can the US maintain deterrence without provoking instability or forcing regional states into hard alignments?

Hard alignment is an option, but it is not where most countries in Southeast Asia—and, for that matter, Northeast Asia—want to be. They do not want to be forced into an “us or them” situation: pick the United States or pick China, but you cannot have both. The reality is they must have both, particularly from an economic perspective. At the same time, the U.S. rightly expresses concern that countries are enjoying prosperity from their dealings with China while also benefiting from a security umbrella provided by the United States.

You now see, especially in the current administration, strong rhetoric about partners carrying a heavier share of the load and not taking U.S. support for granted. Will that ultimately turn into hard positions on choosing the United States versus China? I do not think so. It might initially, but the competition is such that the United States is a little bit behind on several economic fronts: where China is engaging around the world, its pursuit and control of rare-earth minerals, and dependence on these inputs for advanced technologies. There is also the overlap between the Chinese Communist Party and Chinese companies, which creates channels for political influence. It is not a free market.

So the U.S. is trying to help countries understand the risk: not saying you cannot have a relationship with China, but you should proceed with eyes wide open because of how the Party operates the foreign economy. Informing partners is the first way to strengthen deterrence. Physical presence matters as well. The United States needs to be seen in the region so confidence rises and countries do not have to hedge on whether the U.S. will be there. When they see the U.S. at exercises or at ASEAN or APEC—at senior levels—that signals commitment.

When that senior presence is missing and only an assistant secretary or a lower-level representative appears, it causes concern in the region. That weakens deterrence because there is less confidence among countries that are also standing off against China—Vietnam and the Philippines are good examples right now. The U.S. should maintain presence, keep rhetoric consistent, be credible and believable, and stay engaged in ways that build confidence, while also pushing for greater burden-sharing. We can do both. People then do not have to make hard choices. In many cases, they would rather choose the United States, but if they are not sure the U.S. will be there, they will choose for their own security.

How has North Korea’s policy changed on nuclear weapons use, especially on tactical nuclear weapons? Do you believe the traditional deterrence framework is sufficient in preventing conflict?

Yes, the traditional deterrence framework is preventing conflict. There has not been a resumption of war on the Korean Peninsula. There have certainly been incursions, firefights, and losses of life, but not a renewed full-scale Korean War. Deterrence has been successful in that respect.

Deterrence has not, however, prevented the development of nuclear weapons and capabilities. Their policy has evolved over time. I first saw it emerge when I was in Korea in 1996. There were negotiations and framework agreements intended to prevent North Korea from becoming a nuclear-armed country, but then North Korea conducted a nuclear test detonation. That upset the structure of deterrence and undermined confidence that North Korea would follow through on any promises. It hardened beliefs—particularly among conservatives in South Korea, but also in the United States and Japan—that North Korea cannot be trusted.

Over time, their efforts have clearly expanded. They have grown a nuclear arsenal, conducted six tests with increasing yield, obscured where testing was occurring, and prevented inspectors from accessing legitimate sites. From their perspective, nuclear weapons may be the only way to keep the United States focused on the Korean Peninsula. A threat to the United States keeps the U.S. engaged. North Korea gains value from the U.S. presence in Korea and may be the last to want the U.S. to leave, because the U.S. presence counterbalances other powers—Japan, China, and South Korea.

Technologically, the threat to South Korea has grown. Short and medium-range missile systems—and some drone technologies that might carry a nuclear package—put more of South Korea at risk. Meanwhile, intercontinental ballistic missiles extend their reach to the United States and to all U.S. allies, including in Europe. There has also been a rhetorical shift: two years ago, Kim Yo-jong stated that North Korea would have no alternative but to preemptively use nuclear weapons if it determined there was a threat. That was a change from a purely responsive posture. Some of this is rhetoric to achieve deterrence, but it still changes the stability equation.

North Korea has said it will not denuclearize; at times it has also said it would consider denuclearization if the relationship changes and trust is built first. That sequence is the opposite of the U.S. approach, which insists on denuclearization first, then trust, then a new relationship. These are diametrically opposed approaches—where culture and sequencing matter.

You have commanded multinational forces under pressure. How do you approach leadership when balancing competing political objectives, cultural differences, and operational constraints?

It is very challenging. First, appreciate the cultures involved. Second, understand what triggers emotion and drives decision-making, and work within that. As an American commanding in Korea, I communicate to Seoul how America is thinking and what guidance I am receiving. I also communicate to Washington what Seoul is thinking, how the South Korean military is reacting to a given issue, and whether confidence in the United States is where it needs to be. I try to communicate as accurately and precisely as possible.

It is important to operate as an alliance—not to skew it into “just Korean” or “just American.” This becomes important on topics like the transfer of wartime operational control of forces (OPCON transition). That is not a sovereignty question; it is an operational question about who commands the forces provided by both the United States and South Korea. Whether the commander is American or South Korean, that commander is responsible to two nations, not one.

There is a cultural challenge. Would a South Korean general feel comfortable saying “no” to the South Korean president—or advising differently to the United States? Conversely, would an American commander counsel U.S. leadership to follow Seoul’s approach? The idea of OPCON transition should be about overseeing alliance operations from both countries’ contributions—not turning it into a purely Korean organization. If we separate Koreans and Americans in command terms, the alliance is weaker. That is not advisable in an armistice with a growing nuclear state in North Korea.

When peace is achieved and endures, a different relationship may make sense. We are not close to that now. For the moment, a combined force that multiplies the power of both countries is essential to deter—and, if necessary, defeat—North Korea.