Kennedy knew very little about foreign policy and even less about the Far East. I recall there was a big debate between Kennedy and Nixon over the need to defend a couple of puny indefensible and strategically worthless islands, Quemoy and Matsu, which are a very short distance from the mainland. This was in response to the dumb remark that we must not lose even one square foot of land to the evil Commies. The Mainlanders did bombard both islands time after time, but never tried an invasion, because Quemoy and Matsu were worthless.
JFK was very highly overrated. The press loved him, because Nixon hated everyone so much. As I have said, the good thing about JFK was that he was not Nixon. As I recall, Eisenhower was regarded as a stodgy old bore with a frumpy wife by 1960, and Kennedy looked young and virile and Jackie was some sort of fashion plate, so there was a major difference in image between JFK and Eisenhower. It was all about looking modern and stylish.
The US was not a major player in the retreat of the French from Indochina. There was no reason for the US to become involved. But a war was needed to sell weapons and provide an excuse for a draft. The Russians had a draft, so they felt that the US must have one as well.
Another issue was an ostensible "missile gap" that the Russians supposedly had more and better missiles than we did. JFK made this claim, and Nixon, who as a member of the Eisenhower Administration, knew this was a bloody lie but did not dare reveal this, because it was a "secret". The Soviets knew they were outgunned, and the American government also knew this. But it was just terrifying for the US government to reveal the truth, because perhaps the Russians did not know that we knew that they knew. The Soviets put up Sputnick, a huge propaganda ploy, in 1958, and then they shot down Gary Powers in his U2. Eisenhower lied about the existence of the U2 and violating Soviet airspace and forced poor Adlai Stevenson to make a fool of himself in the UN claiming that it was a "weather balloon" . Then the Soviets revealed that they had captured Powers alive and proved that Eisenhower had lied. So enough of the public was convinced that Ike was a lair and that Nixon was a far more incompetent apprentice liar, and JFK won by a hair.