One Nuclear Umbrella, Two Security Commitments
Bibliographic Data
| ID | 24224487 |
|---|---|
| Authors | Jihwan Hwang |
| Year | 2026 |
| Pages | 1-35 |
| Publication date | 2026-10-14 |
| Open Access | Yes |
| Type | ARTICLE |
| Venue | Asian Survey (JOURNAL) |
| Journal identifiers | ISSN: 0004-4687 • E-ISSN: 1533-838X |
| Publisher | University of California Press (PUBLISHER • US) |
| DOI | 10.1525/as.2026.3181058 |
| OpenAlex | W7221813226 |
| Language | EN |
| References cited | 43 |
Why have Japan and South Korea, despite sharing the same US nuclear umbrella, developed distinct extended deterrence arrangements? Previous studies emphasize US-driven, supply-side explanations but fail to explain the persistent divergence between the two allies. I argue that extended deterrence is co-produced by junior allies’ demand, which is shaped by two key variables: external threat and domestic nuclear constraint. Developing a demand-side model and applying it to a comparative historical analysis of Japan and South Korea from the Cold War to the present, I demonstrate that South Korea’s higher threat perception and weaker nuclear constraints, in contrast to Japan’s lower threat perception and stronger domestic constraints, have generated divergent demands for extended deterrence. The study contributes to the literature by shifting attention to demand-side dynamics and offering a theory of differentiated extended deterrence within asymmetric alliances.
asymmetric alliances · Cold war · extended deterrence · Japan · security commitments · South Korea · threat perception · US nuclear umbrella · US-Japan alliance · US-South Korea alliance · International Relations and Foreign Policy · Korean Peninsula Historical and Political Studies · Nuclear Issues and Defense
Balance of Power Redux
Recalcitrance and initiative
Strategies of Extended Deterrence
Public Opinion, Party Politics and Alliance
The Domestic Politics of Nuclear Choices—A Review Essay
Vulnerable US Alliances in Northeast Asia
Japan’s Nuclear Balance
Reducing Nuclear Salience
Why Japan Will Not Go Nuclear (Yet)
To Arm or to Ally? The Patron's Dilemma and the Strategic Logic of Arms Transfers and Alliances
Alliance Coercion and Nuclear Restraint
Veto Players, Nuclear Energy, and Nonproliferation
The Showdown That Wasn't
Strategies of Inhibition
Nuclear Weapons and Existential Threats
Alliance strategy
The Evolution of US Extended Deterrence and South Korea’s Nuclear Ambitions
Loyalty, hedging, or exit
Japan and Extended Nuclear Deterrence
The US and South Korea
International patron-client relationships
Japan’s Nuclear Hedge
Extended nuclear deterrence in East Asia
Correlates of South Korean Public Opinion on Nuclear Proliferation
Network Connections and the Emergence of the Hub-and-Spokes Alliance System in East Asia
Outside the Wire
Trump 2.0 and North Korea
Strategy of Anchoring
US–South Korean Relations at a Crossroads
Under the Umbrella
Signaling Foreign Policy Interests
Credible Nuclear Security Commitments Can Backfire
Promises under Pressure
Why is There No Nato in Asia? Collective Identity, Regionalism, and the Origins of Multilateralism
Signaling Alliance Commitments
Why is there no Nato in Asia?’ revisited
Rewarding loyalty
Japan's National Security Council
| Highly cited | No |
|---|