I have been pondering about the Treaty of San Francisco for a very long time, primarily because of its connection with the Taiwan Question. The Treaty of San Francisco is the peace treaty signed with Japan to end the Pacific War.
In order to understand a treaty, we must understand how law works. The workings of law flow from established principles. Importantly, to understand a peace treaty, one must first know about laws of war. Peace treaties must be read with a military mindset to arrive at accurate interpretations.
Article 2 of the treaty remain one of the most difficult to interpret, because it involved territorial detachment from Japan without naming new sovereigns. I have spent much time trying to figure this out, and finally I did. Those who know about interpreting treaties do not simply reveal this knowledge.
As I continue my journey in learning about the treaty, some interesting things do come up. These are loopholes indeed!
Article 23 - The United States of America as principal occupying power.
During Allied occupation of Japan, the United States acting as the principal occupying power is fact. Military occupation was divided among the Allied Powers, namely United States, China, Soviet Union and Britain. As the United States was the principal, the others were agents acting on behalf of the principal. The statement of United States as principal occupying power is merely a restatement of fact in the treaty, not an elevation of the status of United States to give it more power. Principal occupying power over what is not stated, but it should be interpreted as "over Japan and former sovereign Japanese territories". As territories renounced by Japan remain under Allied occupation, it gives the United States the legal basis to involve itself in Taiwanese affairs.
Article 25 - Allied Powers are not only the nations conducting military occupation in Japan, but also includes other countries at war with Japan and signed the Treaty of San Francisco. Allied Power signatories can be considered occupying power over Japan
Article 25 of the Treaty reads: "For the purposes of the present Treaty the Allied Powers shall be the States at war with Japan, or any State which previously formed a part of the territory of a State named in Article 23, provided that in each case the State concerned has signed and ratified the Treaty. ...."
Japan was under military occupation of the Allies and not United States, China, Soviet Union and Britain acting on behalf of themselves. Each occupying power act as part of a military alliance. But, for the purpose of the treaty, any country that signed and ratified the Treaty of San Francisco is considered an Allied Power. The treaty binds all signatories by law as Allied Powers. Therefore, all the other signatories can be considered occupying powers over Japanese territories. According to the laws of war, because military occupation continues in territorial cessions and detachments after peace treaty and will continue until legal supplantation, Article 25 grants all Allied Power signatories the privileges of being occupying power over former Japanese territories. This can be interpreted to give benefit for Taiwan, as the resolution of the Taiwan Question shall come under scrutiny of the signatories. It is principle that the resolution of the Taiwan Question shall have the assent of the people of Taiwan.
China did not sign the treaty. As a result, China received no benefit from the treaty, except those outlined in the treaty texts. The same goes for Soviet Union. It is obvious that China does not gain sovereign right over Taiwan from the treaty. What more, since China did not sign as an Allied Power signatory, China does not hold the right over Taiwan as occupying power. The Treaty puts China as having no right over Taiwan by law. The Treaty of Taipei, an extension of the Treaty of San Francisco, recognised Chinese right of jurisdiction over Taiwan but not sovereignty. But the basis for right of jurisdiction is lost when Japan denounced the Treaty of Taipei later.
The US resorted to shutting China out of the Treaty of San Francisco as a Cold War containment strategy. That puts China on the opposing side with the Allies over resolution of the Taiwan Question.