Final answer:
Western European concerns at the outset of the invasion of South Korea were focused on the potential spread of communism and the security implications for the world.
Step-by-step explanation:
At the outset of the invasion of South Korea, Western European concerns were primarily centered around the potential spread of communism and the implications for global security. The United States was concerned about maintaining its credibility as a defender of democratic nations and preventing the domino effect of communist victories. Additionally, the Korean situation occurred shortly after the communist takeover of neighboring China, which further heightened concerns about the expansion of communism in the region.