The correct answer is Mexico.
Because of Mexico and their gulf of Mexico, the United States cannot control the entire gulf area. If the area changed hands and went to the United States, they could unite the two gulfs and have a huge control over the land and the ports in the new world. However, that's probably never going to happen so it stays this way for now.
Answer: On April 6, 1917, the United States formally declared war against Germany and entered the conflict in Europe. Fighting since the summer of 1914, Britain, France, and Russia welcomed news that American troops and supplies would be directed toward the Allied war effort.
Explanation: