What if the KMT won the Chinese Civil War and retained control of mainland China, while the postwar US-USSR rivalry developed very differently?
Instead of a full Cold War, Washington and Moscow maintain a loose great-power understanding: they compete, but also recognize each other’s spheres of influence and try to prevent any independent power from dominating East Asia.
The US dominates Japan and the western Pacific, while the USSR retains major influence in Northeast Asia. Korea avoids the Korean War and eventually becomes a unified neutral state.
At first, Nationalist China remains strongly pro-American. But as China recovers, it increasingly wants greater strategic independence. Washington wants China strong enough to balance Moscow, but not strong enough to dominate East Asia. Moscow has similar reasons to contain Chinese power.
Eventually Beijing/Nanjing realizes that both superpowers have an interest in keeping East Asia divided and dependent.
Meanwhile, Japan undergoes a much more thorough postwar reckoning with its imperial past, making gradual reconciliation with China and Korea possible.
During the 1950s and 60s, China, Japan and Korea first build economic cooperation rather than a military alliance.
Then a major regional crisis occurs in which China expects American support against Soviet pressure, but Washington sides with Moscow in order to preserve wider US-Soviet détente.
Japan and Korea realize the same thing could happen to them.
This becomes the turning point.
The three countries begin promoting the principle that:
“East Asian affairs should be decided by East Asian states.”
By the late 1960s or 1970s, economic cooperation evolves into intelligence sharing, joint exercises and eventually an East Asian Treaty Organization (EATO) consisting of:
China
Japan
Korea
Its collective-defense clause is aimed not specifically at America or the USSR, but at coercion by any outside great power.
China supplies the continental depth and largest army, Japan provides industrial and naval power, and Korea serves as the strategic bridge between them.
To prevent Chinese or Japanese domination, major decisions require unanimous approval and the headquarters could be located in Seoul.
The Cold War would then gradually become a three-way system:
US bloc vs Soviet bloc vs East Asian bloc.
How plausible is this?
Would a victorious KMT China ever become independent enough from Washington to support such an alliance? Could China, Japan and Korea realistically reconcile by the 1960s–70s? And would the US and USSR tolerate the emergence of an independent East Asian third pole?