From what I understand, the US emerged as a world superpower after World War II in part because the war wasn't fought on the U.S. mainland, so it's infrastructure remained largely intact.
The same can't be said for other two allied superpowers, the USSR and the British Empire. Both nations were devastated in the war, but following the surrender of Germany and Japan, the USSR seemed to recover quite quickly whereas Britain's empire declined.
Given the enormous losses by the USSR (including the deaths from the Great Purge), how were the Soviets able to retain such a vast global influence when the British couldn't?
Thanks for any answers.
So /u/ThePutback wrote about the differences in how the nations were "devastated" in the war, but I wanted to expand on another difference between the British Empire and the Soviet Union:
The Soviet Union was the ideological leader of an increasingly significant portion of the world in the wake of WW2.
So while the British Empire physically possessed numerous colonies and protectorates across the world, the Soviet Union had the virtual ideological ownership of many nations and revolutionary groups all around the world.
This only grew as Europe de-colonized rapidly after WW2 when many new governments and revolutionary groups aligned themselves with Eastern bloc (regardless of how much adherence they had to Marxist/communist ideology).
Whether it was the split between the Koreas immediately after WW2, or the ideological struggle between the Vietnams split after the French withdrew in the 1950s, the wave of pan-Arabism in the 1950s and 1960s that was closely aligned with the Soviet Union, or the formation of People's Democratic Republic of Yemen after the British protectorate there ended in the late 60s, or the fight over Angola after independence from Portugal in the 70s... the Soviet Union possessed a massive amount of power with a large bloc of nations in the world throughout all the decades of the Cold War.
The British simply didn't have the manpower or financial situation to maintain such an extensive network of colonies, especially as de-colonization often ended up in bloody affairs in many places around the world. Furthermore, the backbone of the British Empire, the Royal Navy, could no longer compete with the US or even the Soviet navies.
In fact, by the end of WW2, the UK had already ceded domination of the seas to the United States and navies are very expensive. For instance, the US maintained at times during the Cold War over 16 fleet aircraft carriers simultaneously (over 24 of them in different configurations forms in 1960 alone), and by the end of the Cold War in 1991 had 14 supercarriers in simultaneous service.
In contrast, the UK retired its last fleet carriers using conventional catapult and arresting gear configurations in the 1970s. No new designs were bought or commissioned, and the UK nearly sold its remaining light carriers using Harriers until the Falklands War stopped their sale. Add on the humiliation of the Suez Crisis, and the UK finally pulling its last carrier out from Hong Kong in the 1970s, the end of the "East of Suez" era for British power projection was evident. And, without the ability to project power to defend its colonies and protectorates abroad, decolonization only hastened and many of those protectorates became aligned with the US, which filled in the role that the British once did (such as the end of protectorate status for the Trucial States, which would form Qatar, Bahrain, and the UAE, nations that have US military bases/forces stationed there).
Britain wasn't exactly "devastated" by the war in the same way as the USSR. German planes actually did relatively little damage to Britain's infrastructure, which remained largely intact and increased in productive capacity throughout the war. But Britain financed her role in the war by heavy borrowing; when the war ended, she could not maintain the expense of an overseas empire and service her now-enormous debt at the same time. So she was devastated financially.
The USSR was "devastated" in the more conventional sense, having an enormous chunk of her agricultural lands taken away and losing 25 million people (the high estimate of the death toll of the Great Purge is about 300,000, so not very significant compared to WWII). But her industrial capacity was not greatly affected, as the USSR managed to evacuate most of their factories to the unreachable Urals early in the war; and the USSR got back all its lost agricultural land and then some when the war ended (they also more than made up for their lost population by absorbing Poland, half of Germany and other parts of Eastern Europe). Moreover, while they did do some conventional borrowing, most of the aid they received from the West was Lend Lease material from the US or outright "gifts" from Britain, so they did not find themselves facing a crushing national debt after the war.