Since China and Japan is now having a dispute over the Tiaoyutai Isles (or Senkaku, as they call it), together with a strong mutual resentment... I wonder whether it's possible for a stable Sino Japanese alliance.
Historically there were three instances when the two country really got near to become allies, first before the Sino-Japanese War, when Japan felt that her own independence was threatened by Russia. Second time was after the Russians took Mukden, which led to the Chinese feeling of being betrayed by Russia, and a strong pro-Japan sentiment. Third was during late Cold War, when the PRC was considering selling ballistic missile to Japan to counter a (perceived) Soviet threat.
Could those alliances become permanent had history turned differently. Do we need a bigger Russian threat?
Any proposal involving a Chinese puppet by Japan or Japanese Puppet by China would be rejected, and no politicking in this thread.