Why Isn't the US Flag Flying over Taiwan?
Most countries which have engaged in war in the last several hundred years have seen numerous instances of their flag flying over foreign territory. Nevertheless, it is probably a surprise to most persons that there are actually rules (aka "established precedent") regarding such matters. For the most part, these laws have not been fully codified, hence they are referred to as "customary laws."
The Customary Laws of Flag Raising
Looking back at the early days of the United States, there was a British invasion of Castine, Maine, during the War of 1812 and the British flag was raised. Such a military action is not "annexation," rather Britain's position as the conqueror means that Britain will be "the occupying power." Any matters regarding territorial cession are specified in a post-war peace treaty. In the Treaty of Ghent, this section of Maine was not ceded to the British, so of course the British flag came down and the US flag went back up.
However, even from this simple British example we can get an insight into certain "customary laws." Specifically, we see that
Can such a customary law formulation help us to understand Japanese attacks on the USA after Pearl Harbor? During WWII, Japan acquired Guam and portions of the Aleutian Islands. These territories were under military occupation by Japan, but not annexed. Japan was the conqueror and the occupying power, so the Japanese flag was flying. Yes, our four point formulation works exactly.
US Attacks on Japanese Overseas Territories
What about US attacks on Japan? During WWII, the US acquired many overseas territories of Japan, and Iwo Jima was one famous example. The United States was the conqueror and the occupying power. The US flag was flying. In the post-war San Francisco Peace Treaty (SFPT), Iwo Jima wasn't a territorial cession, so US troops left the area, and the Japanese resumed control. Again, our four point formulation gives the correct framework.
Now let's turn to Formosa and the Pescadores, aka "Taiwan." Taiwan had been ceded to Japan in the 1895 Treaty of Shimonoseki. After Pearl Harbor, the United States declared war against Japan on Dec. 8, 1941. During the WWII period, over 96% of all military attacks against (Japanese) Taiwan were conducted by US military forces, so it is clear that the USA acquired Taiwan under the principle of conquest. According to the customary laws of warfare, the United States is the conqueror and the occupying power. US military troops were in Taiwan in early September 1945.
However, at this point some unusual events occurred. In General Order no. 1, Gen. MacArthur delegated the holding of the surrender ceremonies to Chiang Kai-shek of the Republic of China. After the surrender of Japanese troops in Taiwan on Oct. 25, 1945, only the flag of the ROC continued to fly, and the ROC military forces announced "Taiwan Retrocession Day," saying that Taiwan had been annexed by China.
Clearly, these actions fall entirely outside of the four point formulation given above. While it is true that CKS held the surrender ceremonies on behalf of the Allies, nevertheless legally speaking the ensuing military occupation of Taiwan is being conducted on behalf of "the conqueror" and "the occupying power" -- and that is the United States. Hence, after the surrender ceremonies, the flag of the United States should have continued to fly.
In Taiwan, the ROC is not "the occupying power," it is only "an occupying power," or more properly "a subordinate occupying power" (i.e. "proxy occupying forces"). The ROC is exercising delegated administrative authority for the military occupation of Taiwan under the United States Military Government (USMG). Announcement of the annexation of Taiwan territory is a war crime.
Taiwan under the SFPT
On Oct. 1, 1949, the People's Republic of China was founded, and in the ensuing months the remnants of the ROC government fled to occupied Taiwan. Some two years later, in late April, 1952, the SFPT came into force. Japan renounced the sovereignty of Taiwan, but no receiving country was designated. Hence, Taiwan remained under the administrative authority of USMG. Surprisingly however, the flag of the ROC continued to be displayed everywhere.
The text of the San Francisco Peace Treaty (SFPT) contains 27 Articles. After the coming into force of the SFPT, the Allies disbanded. Notably, the SFPT did not award the territorial sovereignty of Taiwan to the ROC. Moreover there are no Articles in the SFPT which can be interpreted to say that the signatories were designating any role for the ROC government to play in the continuing governance of Taiwan after late April 28, 1952. Conclusion: At this point in time, the flag of the ROC should have come down.
As a result of military action in WWII, both Taiwan and Iwo Jima were conquered by United States military forces. Iwo Jima wasn't ceded to the United States, so of course the US flag came down. Taiwan wasn't ceded to the ROC, so why is the flag of the ROC government in exile still flying? Where is the flag of the United States military authorities? That's the same flag that US civilians know as "the star-spangled banner."
As we get nearer to Flag Day on June 14, this is one question which all patriotic Americans should be seriously concerned about: "Why isn't the US flag flying over Taiwan?"