Why do you think the United States was willing to defend South Korea from North Korean communist aggression but not answer Vietnam's request for help from French aggression?

The U.S was willing to help aid in South Korea, only to stop the North Korean's Aggression. While not directly committing forces to the conflict itself.

Explanation:

although world war i began in 1914, the united states did not join the war until 1917. the additional firepower, resources, and soldiers of the u.s. to tip the balance of the war in favor of the allies. remaining neutral. when war broke out in 1914, the united states had a policy of neutrality.

i believe the answer is d.