By Dr. James M. Minnich

Honolulu—January 16, 2026

South Korea’s renewed interest in nuclear-powered attack submarines (SSNs) is often framed as a prestige-driven pursuit. In Episode 2 of Strategic Voices, Professors James Minnich, Shyam Tekwani, and Lami Kim moved beyond that shorthand to ask a harder question: what would SSNs actually change for deterrence, alliance dynamics, and the stability of Northeast Asia—if South Korea proceeds? Treating the issue as symbolism alone obscures the alliance, industrial, and nonproliferation consequences that would follow.

Propulsion, Not Nuclear Weapons

Minnich opened the discussion by drawing a deliberate boundary: “This is not a discussion about nuclear weapons. It’s about propulsion—endurance, stealth, and sustained presence in an intensifying undersea theater.” That distinction matters because debates over SSNs in Northeast Asia frequently slide from engineering into nuclear politics, where signaling and perception can overwhelm operational realities.

Kim then outlined the policy trigger. Under the bilateral civil nuclear cooperation framework—commonly referred to as the “123 Agreement”—South Korea’s use of U.S.-origin nuclear technology for military purposes is constrained. A late-2025 summit opened a political door, but with a significant caveat: the possibility that SSNs could be built at the Hanwha-owned shipyard in Philadelphia. That condition immediately raised questions about nuclear certification, workforce readiness, timelines, and cost. What changed was not the regional deterrence environment, but Washington’s willingness—under specific economic and industrial conditions—to reconsider a long-standing prohibition.

Three Lenses: Justifications, Uncertainties, Warnings

The episode organized the debate around three analytical lenses drawn from the assigned readings.

Justifications. Kim summarized the affirmative case as it is often articulated in Seoul: SSNs could help counter North Korea’s evolving capabilities, strengthen allied deterrence, and enable broader maritime contributions. Minnich challenged the tendency to overclaim. South Korea’s most acute threat remains North Korea’s mobile, land-based missile force—capabilities that SSNs are not designed to deter. The panel treated nuclear-powered submarines as potentially useful, but far from automatically decisive.

Uncertainties. This became the center of gravity of the discussion. Tekwani reframed the issue by arguing that SSNs are never “just submarines,” but long-term commitments shaped by time horizons, alliance trust, and nonproliferation politics. He invoked Run Silent, Run Deep to illustrate how undersea power derives from endurance, restraint, and the uncertainty it imposes on adversaries—not from constant action. The analogy resonated because the panel repeatedly returned to what SSNs actually buy: persistence and signaling, if they can be fielded and sustained.

Kim highlighted practical constraints that are often underplayed. These include whether the future undersea environment becomes increasingly transparent due to advances in sensing; whether personnel systems can sustain monthslong deployments; and whether opportunity costs crowd out nearer-term investments in air-independent propulsion (AIP) submarines, unmanned systems, and anti-submarine warfare. Some critics warn that long-delayed SSN programs risk becoming “billion-dollar coffins” if sensing technologies outpace submarine stealth.

Warnings. The clearest caution came from treating AUKUS as a stress test rather than a template. The Australian experience underscores the realities of extended timelines, industrial bottlenecks, and persistent nonproliferation controversy. Minnich and Kim also flagged the arms-race narrative—particularly if North Korea acquires external assistance in naval nuclear propulsion—and the broader “hedging” concern: that SSNs could be interpreted as part of an “everything but the bomb” pathway, regardless of Seoul’s stated intent.

A Closing Synthesis: Discipline Matters More Than Hulls

Taken together, these perspectives point to a conclusion that is less technical than political. The episode’s most durable takeaway came in Tekwani’s line: “Nuclear submarines only reinforce deterrence when they are tightly bound by alliance discipline and nonproliferation constraints.” Without those limits, they risk undermining the very stability they are meant to protect. The strategic case for South Korean SSNs, then, is less about reactors and hulls than about governance—how the program is framed, safeguarded, financed, and sustained across political cycles. Whether built in Geoje or Philadelphia, the most consequential variable will be alliance trust, and the discipline with which Seoul and Washington tie any SSN program to regional stability rather than escalation.

Referenced in this Episode:

• George M. Moore (2025). Will South Korea Acquire Nuclear Submarines? It’s Not Certain. PACNET.
• Jihoon Yu (2025). What AUKUS Teaches Seoul about Nuclear-Powered Submarines. The Strategist.
• Bong-Geun Jun, Why the Republic of Korea Needs Nuclear-Powered Submarines. Korea.Net.
• Lami Kim, Everything but the Bomb: South Korea’s Nuclear Hedging Strategy.Stanford University Press (forthcoming).
• Edward L. Beach (1958) Run Silent, Run Deep.

Visit the Strategic Voices webpage to explore upcoming and past episodes.