Which two nations emerged as superpowers after World War II? Which nation was in the better post-war position, and why?

Both the Soviet Union (USSR) and the United States emerged from World War 2 as the leading world powers. Joseph Stalin, the leader of the USSR, managed to claim several Eastern European territories like Eastern Germany during the war and convert them to the accepted method of government at the time: Communism, while America emerged from the war with a blossoming domestic economy, economic and political ties to most developed nations around the world, and superior military research and production (ie. nukes). The USSR when compared to the USA was actually not in quite as good of a position in the world theatre; they had isolated themselves after leaving NATO and were left without any real allies, while America was able to establish itself as the leading world power. What may have tipped the scale in terms of post-war conditions was a combination of successful nuclear tests by the USSR as well as the emergence of a Communist China, but other than that, unsuccessful military ventures for America like the Korean War also tipped the scale to something much more even for many years to come.

A.among Russia, Britain, and the shah of Persia

Explanation:

In 1907. The Imperial ambitions of Britain and Russian were conciliated, as a division took place, the north of (Today Iran) became under influence of Russia, the south becoming influenced by England and in the middle the formation of a puppet state that was favorable to both Empires.

The civil uprisings of 1905, posed some treats to the interests of these nations that would not encourage liberal reforms in the country. Neither of them accepted the social changes and then resolved to form The Anglo Russian Entente, in 1907, the frontiers are then shaped to promote a region that otherwise would have turned unfavorable to the status quo.

Under the argument of a neutral zone, the middle of Persia remained in control together with some foreign delegates that always promoted traditional policies.

See the image below for reference: