Well there were also other factors. The economic "Finlandization" of Germany, Korea and to a lesser extent Vietnam throughout the 1950s, rather than create a divided political and economic set of nations , created a mixed/collaborative system whereby both the Warsaw Pact and European Economic Commonwealth had a trading partner in Europe, and both China and Japan had a common trade partner.
It didn't help matters that Germany and Japan were able to buildup their military forces starting in 1991,...
In regards to America, according to Cheney apologists, the blame belongs to the economic policies of President Edward M. Kennedy and Jerry Brown, and the "lack of willingness to prosecute war against the American Indian Movement ...
I will add onto this that when the COINTELPRO Scandal hit during late 60s, it added to the instability with what you mentioned, AIM. Man when that whistleblower from the FBI leaked everything, things got worse as many of the groups targeted simply became more emboldened to fight for their cause whether the black nationalists, white supremacists, communist, socialist, the New Left, etc is what I think is the big cause for the downfall of America.
One must not forget the fall of the US and USSR also let other nations and alliances to rise.
Japan, after it was able to fix itself, form the Pacific Bloc with South Korea, and other Asian/ Oceania to try to stand they own and not do what China's say.
South America has grow since what happen to the US and Russia with Argentina and Brazil in the lead.
I prefer the Pacific Bloc to be called a hegemony of South Korea and Japan. Japanese and Korean media really has become quite global though it still has to compete with Hollywood. California is quite a major power in the Pacific bloc to. Considering how much technology/innovation is pumped out from the Golden state and that Hollywood continue to rake in blockbuster profits each year.
Also to add to California that we annexed most of the West except the PNW[1] so we could have access to Colorado water. But we really made the other member states of the former USA cautious to us but specifically, increasing tensions with Texas especially when we are pretty much rivals in former America.
I think that when the IJ annexed Karafuto and Chishima [2], that marked the signal to the world that Japan really was going to a major force. Chishima archipelago minerals of Pyrite, Sulfur, and Polymetal is a major strategic value with Karafuto oil and gas deposits.
You can add in the PHL as well. Macapagal -Arroyo did a fine job returning the Philippines from its economic slump after the collapse of America by focusing trade with members of the Pacific bloc. Add into the fact that the Philippines has a major BPO industry when that we overtook India as call center capital of the world.
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[1] Pacific Northwest
[2] Karafuto is the Japanese name for Sakhalin and Chishima for the Kurils
OOC: I removed South Asia from becoming "fire" since an event like that will add too much into the DBWI.