I love the post, but this seemed odd. How could the world not notice? It seems a bit strange that, even amidst great power tensions, the resurrection of one of great powers in the Second World War would have been missed. At the very least it would have been important to the world for the possibilities of greater instability in Asia. If Nazi Germany had returned I think someone would have noticed.
On another note, although China might be troubled by Japanese intervention, and will surely use this as an opportunity to score some propaganda points with its own population in terms of vilifying American and NATO for association with the Japanese, their basic calculations about the war should not have changed. I do wonder if China will make any moves against Taiwan while America is busy? While it is a big risk, the Americans might not want to risk war with China over a non-ally, and actually defeating the Taiwanese without American support shouldn't be too difficult.
It's possible, but that would assume the US is willing to take the huge hit to international trust if it allows the PRC to do such a thing. Such an allowance by the US would most likely be viewed as the US having failed in its duty to defend its allies, and considering that is a huge part of what makes NATO work, I honesty doubt China would risk an invasion of Taiwan.
Similar to how the US crossing the 38th parallel into North Korea triggered the PRC counterattack, an attack on Taiwan would mostly likely force the US into a corner: either abandon Taiwan and lose face internationally or counterattack and trigger war, something neither of them want, but a decision the US may ultimately decide to be a necessary one. Not to mention that such an war would inevitably force China into the USSR camp, something neither the US and Southeast Asian allies nor any countries that follow the Chinese version of communism want.
And even if they do somehow manage to take over Taiwan and stave off any US response, I doubt China's international image is going to look good afterwards. Assuming they do go through with such an act, the PR hit may surpass even the aftermath of the Korean War. Say goodbye to any semblance of diplomatic relations with the western bloc, and say hello to a treacherous "alliance" with the USSR and its allies (if it even still exists after WWIII). Not to mention any further moves into Europe or Asia are going to be watched and countered much more vigorously by the US.
In short, imagine Francoist Spain after WWII: cut off diplomatically, politically, and economically until some other threat cropping up in the region persuades the western bloc to open up to the PRC again, which may take decades. And in that time, China's economy will be suffering, potentially creating "lost decade(s)" a la Japan style.
