The U.S because they stole land from the Native Americans in a violent and cold way and forced them to go down the trail of tears.
It made it much harder for a submarine to torpedo a cargo ship and escape without being attacked. Thank you for posting your question here at brainly. I hope the answer will help you. Feel free to ask more questions.
Answer:
Portugal
Explanation:
Portugal initiated the era of Atlantic exploration in the 15th century