Answer:
The answer to the question: How did Kennedy´s actions in Southeast Asia set the stage for future conflict, would be, that, through his support of counterinsurgancy movements, to the point of sending off American personnel and troops, to countries such as South Vietnam and almost to Laos, paved the ground for what later became the much bigger Vietnam War.
Explanation:
Ever since he was a senator, John F. Kennedy became interested in international politics, and especially the role that America needed to play in stopping Communism, and particularly, the Soviets. Thus, when he assumed power as President, he furthered this ideal by supporting counterinsurgency movements that wished to expel Communism from their countries. This was the case of Cuba, with the Bay of Pigs incident, and later on in Southeast Asia, when conflict began between North and South Vietnam, and later, in 1961, in Laos. Kennedy wished to repel Communism and thus he stepped up American military involvement, though not direct involvement. He also later on used diplomacy, recognizing that direct conflict was useless. However, his steps still prepared the ground for the escalating conflict that disembarked into the terrible Vietnam War.