By: HISTORY.com Editors
SEATO established
Having been directed by President Dwight D. Eisenhower to put together an alliance to contain any communist aggression in the free territories of Vietnam, Laos and Cambodia, or Southeast Asia in general, Secretary of State John Foster Dulles forges an agreement establishing a military alliance that becomes the Southeast Asia Treaty Organization (SEATO).
Signatories, including France, Great Britain, Australia, New Zealand, the Philippines, Pakistan, Thailand, and the United States, pledged themselves to “act to meet the common danger” in the event of aggression against any signatory state. A separate protocol to SEATO designated Laos, Cambodia, and “the free territory under the jurisdiction of the State of Vietnam [South Vietnam]” as also being areas subject to the provisions of the treaty. The language of the treaty did not go as far as the absolute mutual defense commitments and force structure of the NATO alliance, instead providing only for consultations in case of aggression against a signatory or protocol state before any combined actions were initiated. This lack of an agreement that would have compelled a combined military response to aggression significantly weakened SEATO as a military alliance. It was, however, used as legal basis for U.S. involvement in South Vietnam. SEATO expired on June 30, 1977.
Vietnam War Timeline
Whether they volunteered or were drafted, 1 out of 10 soldiers were injured or killed during Vietnam.
Also on This Day in History
Discover more of the major events, famous births, notable deaths and everything else history-making that happened on September 8th
Related
Vietnam War
41 videosThe dramatic rooftop photo was long mistakenly misidentified.
The conflict in Vietnam ended in turmoil with the largest helicopter evacuation of its kind in history.
After 10 days of bruising battle, U.S. forces took the hill, only to abandon it days later. Sniper fire was so intense, one soldier called it 'a human meat grinder.'
About the author
HISTORY.com works with a wide range of writers and editors to create accurate and informative content. All articles are regularly reviewed and updated by the HISTORY.com team. Articles with the “HISTORY.com Editors” byline have been written or edited by the HISTORY.com editors, including Amanda Onion, Christian Zapata, Cristiana Lombardo and Adrienne Donica.
Fact Check
We strive for accuracy and fairness. But if you see something that doesn't look right, click here to contact us! HISTORY reviews and updates its content regularly to ensure it is complete and accurate.
Citation Information
- Article Title
- SEATO established
- Author
- HISTORY.com Editors
- Website Name
- History
- Date Accessed
- October 29, 2026
- Publisher
- A&E Television Networks
- Last Updated
- May 27, 2025
- Original Published Date
- November 16, 2009