Final answer:
John F. Kennedy described Vietnam as the 'cornerstone of the free world in Southeast Asia.' He considered Asia to be a critical area for containing communism, and Vietnam played a central role in this strategy.
Step-by-step explanation:
According to historical records, John F. Kennedy referred to Vietnam as the 'cornerstone of the free world in Southeast Asia.' He believed that Asia was a crucial region for containing the spread of communism and saw Vietnam as a key battleground in this effort. Kennedy approved covert operations and military assistance in Southeast Asia, indicating the significance he placed on the region.