Answer:
The Gulf of Tonkin settlement (1964) provided support to Congress for authorization, without formal declaration of war, for the use of military forces in Southeast Asia, specifically in Vietnam.
Step-by-step explanation:
The so-called "Tonkin Gulf Incident" was the pretext on which Lyndon B. Johnson's government was based to attack Vietnam in an undeclared war that has dragged on for more than a decade, killing more than 2 million Vietnamese, 50 hundreds of thousands of Cambodians and Laotians, and deliberately causing the destruction and chemical contamination of millions of hectares of virgin forest and field of cultivation. The consequences of such a disaster are still palpable today in many ways.
On August 7, 1964, the US Congress approved the "Tonkin Gulf Resolution," authorizing the president to use the military against Vietnam as a necessary measure to prevent further aggression. A false pretense of aggression was used again to justify a war.