haha! 美日戰爭of course is between US and Japan. But

There was also Japan-China, Japan-Russia, etc.. Japan vs Allies. 日本投降 was to the ALLIES, not to US alone. ALLIES are the conquerer and US was ONE of them, even if they did fight Japan in the Pacific, it still means US was one of THEM.

Justifying your arguement using definition from the Expanisonism period of US history won't get you anywhere either in public opinion or US politicians. There are many cases in which new Supreme Court redefined a previous Supreme Court's definition of the Constitution. Why don't you try arguing in US court of law if you have such a "solid" case?

陳總統要動到中華民國憲法，把台灣土地圈入中華民國的領土範圍，美國為何馬上跳出來說：「Do not permit!」?

That is because he want to US as a shield against possible PRC attacks. US won't let him use itself as a shield since US also is the main supplier of ROC arms. This gave them a great deal of influence over ROC politics and they also don't want to lose the arms business until ROC is dry of funds. So of course it will stop Chen from endangering the profitable business it has with ROC. Also it has great amount of financial business with PRC. It don't want to lose them in a war caused by both sides. In the end, US will only support what it sees as the most profitable for itself in ROC politics.

I haven't found any words stated by US that says "Do Not Permit". Please gave a original link to such rebukes said by US to ROC.