1960 treaty establishing the current Japanese-American military alliance
The 1960 U.S.–Japan Security Treaty formalized a mutual defense alliance that has governed American military presence in Japan for over six decades.
Key Facts
- Treaty signed
- January 19, 1960
- Treaty took effect
- June 23, 1960
- Replaced earlier treaty of
- 1951 (signed with San Francisco Peace Treaty)
- Minimum term
- 10 years; indefinite unless terminated with 1 year notice
- Anpo protests
- Largest popular protests in Japanese history
- Duration unamended
- Longest-lasting great-power treaty since Peace of Westphalia (1648)
By the Numbers
Location
Cause → Event → Consequence
The original 1951 U.S.–Japan Security Treaty, signed alongside the San Francisco Peace Treaty ending World War II, was widely criticized in Japan as unequal. It allowed the United States to deploy forces from Japanese bases across East Asia without consulting Japan, made no clear commitment to defend Japan, and permitted U.S. intervention in Japanese domestic disputes, prompting demands for renegotiation.
On January 19, 1960, the United States and Japan signed a revised Treaty of Mutual Cooperation and Security in Washington, D.C. The new treaty established explicit mutual defense obligations, required the U.S. to consult Japan before mobilizing forces based there, and removed the clause permitting interference in Japanese domestic affairs, replacing the asymmetric 1951 arrangement with a more reciprocal framework.
The treaty's ratification triggered the massive Anpo protests, the largest demonstrations in Japanese history, forcing Prime Minister Kishi Nobusuke to resign. Despite the unrest, the treaty took effect on June 23, 1960, and has remained unamended ever since, underpinning the U.S.–Japan alliance. It also spawned ongoing bilateral institutions for cultural, scientific, and economic cooperation.
Political Outcome
A revised, more reciprocal U.S.–Japan mutual defense treaty took effect, replacing the unequal 1951 agreement and establishing an enduring military alliance with ongoing bilateral cooperation bodies.
Asymmetric 1951 treaty granting the U.S. unilateral rights to base forces in Japan and intervene in domestic affairs without mutual defense commitment
Mutual defense alliance with consultation requirements, equal obligations, and removal of U.S. right to intervene in Japanese domestic affairs