Question

European colonization and interference in the Western Hemisphere was held in check by the:

Good Neighbor policy
Big Stick policy
Watchful Waiting
Monroe Doctrine

Answer 1

Monroe Doctrine

Step-by-step explanation:

European colonization and interference in the Western Hemisphere was held in check by the "Monroe Doctrine," since this stated that the US would treat expansion into the west as an act of aggression.

Answer 2

European colonization and interference in the Western Hemisphere was held in check by the "Monroe Doctrine," since this was issued by the United States in an effort to claim sovereignty over the entire region.