Answer:
Six western powers were in Southeast Asia. They are France, Great Britain, the Netherlands, Portugal, the Dutch, Spain, and the United States.
Explanation:
I researched the answer. My research lead me to the UNIVERSITY OF HAWAI'I AT MANOA. Here is the link if you want to read the article: https://guides.library.manoa.hawaii.edu/c.php?g=105536&p=687513.
