Answer :
US and Russia-their competition between each other then led to the Cold War later on.
The two countries that became global superpowers and created a bi-polar world order for almost the next five decades were the Soviet Union and the United States. Following the end of WWII and the rise of the Soviet Union and the United States a new kind of war or conflict developed between the Soviet Union and the United States for influence and power globally. This war was called the Cold War and dominated much of international politics for the latter part of the 20th century.