The could be this one Isolationism toward Latin America, but involvement in Europe. That policy was called Roosevelt Corollary. or this one <span>They were also protecting American business interests all over the world.</span>
I believe it is Viceroyalties. Hope that helps
James Monroe was the 5th president
Barrier islands serve as the first protection for the mainland. They take the first hit and slow down the hurricane/reduce impacts. Because of this, lack of barrier islands would cause the mainland to be flooded even more, which would cause land loss.