Defense Policy
Respondents evaluated pairs of hypothetical Japanese defense policy packages and chose which package they preferred. Results are reported as marginal means (Pr(chosen) with 95% CIs).
Wave 2023 April
Respondents evaluated packages described along four attributes: the primary policy objective, the greatest perceived threat to Japan, new strategic domains of emphasis, and the source of defense funding.
Results
課題（日本語）: 仮想の日本の防衛政策パッケージのペアを評価し、どちらを好むかを選んでください。
Task (English): Respondents evaluated pairs of hypothetical Japanese defense policy packages and chose which package they preferred.
| 属性 (Attribute) | 選択肢（日本語） | Levels (English) |
|---|---|---|
| 主要な目標 (Primary Goal) | 外交を重視し、決して戦争に巻き込まれないようにする; 積極的に国際社会に関与し、平和維持に貢献する; 軍事的抑止力を強化し、国民と領土を守る | Prioritize diplomacy, avoid war; Engage internationally, contribute to peacekeeping; Strengthen military deterrence |
| 日本にとって最大の脅威 (Biggest Threat) | 北朝鮮の核開発; 中国の覇権主義; アメリカの戦争に巻き込まれること | North Korea’s nuclear weapons; China’s expansionism; Getting drawn into US wars |
| 重視するべき新たな分野 (New Domain) | サイバーセキュリティー; 宇宙; 経済安全保障 | Cyber security; Space; Economic security |
| 防衛費の財源 (Budget Source) | 増税; 国債; 社会保障費など他の予算を削る | Tax increase; Government bonds; Cut social spending |
From Wave 2023 April.
Wave 2026 February
Executive Summary
Japanese respondents favor diplomatic over military approaches to defense, and strongly oppose nuclear weapons acquisition. Packages emphasizing diplomacy are preferred over those emphasizing deterrence. Among perceived threats, North Korea’s nuclear program and China’s expansionism are rated similarly, while the prospect of being drawn into US wars is also salient. On nuclear policy, the vast majority prefer upholding the Three Non-Nuclear Principles; packages proposing nuclear sharing with allies or Japan acquiring its own nuclear weapons are markedly less preferred. Funding defense through cuts to social spending is the least preferred budget option.
Results
課題（日本語）: 仮想の日本の防衛政策パッケージのペアを評価し、どちらを好むかを選んでください。
Task (English): Respondents evaluated pairs of hypothetical Japanese defence policy packages and chose which package they preferred.
| 属性 (Attribute) | 選択肢（日本語） | Levels (English) |
|---|---|---|
| 主要な目標 (Primary Goal) | 外交を重視し、決して戦争に巻き込まれないようにする; 積極的に国際社会に関与し、平和維持に貢献する; 軍事的抑止力を強化し、国民と領土を守る | Prioritize diplomacy, avoid war; Engage internationally, contribute to peacekeeping; Enhance military deterrence |
| 日本にとって最大の脅威 (Biggest Threat) | 北朝鮮の核開発; 中国の覇権主義; アメリカの戦争に巻き込まれること | North Korea’s nuclear weapons; China’s expansionism; Getting drawn into US wars |
| 重視するべき新たな分野 (New Domain) | サイバーセキュリティー; 宇宙; 経済安全保障 | Cyber security; Space; Economic security |
| 防衛費の財源 (Budget Source) | 増税; 国債; 社会保障費など他の予算を削る | Tax increase; National bonds; Cut other spending (e.g., social security) |
| 核保有 (Nuclear Policy) | 非核三原則を堅持するべき; 同盟国による日本での核配備（核共有）を検討するべき; 日本の核保有を検討するべき | Uphold Three Non-Nuclear Principles; Consider nuclear sharing with allies; Consider possessing own nuclear weapons |
From Wave 2026 February.