
There was also the flag of the defunct Republic of VIetnam
https://vietnguyen.info/2021/theres-a-reason-the-south-vietnamese-flag-flew-during-the-capitol-riot
The depth of anti-communist feeling in the Vietnamese community, which includes many military veterans and former government officials, meant that it has always leaned strongly Republican. While Asian Americans as a whole voted 2 to 1 for Joe Biden over Trump, Vietnamese Americans supported Trump over Biden, 57 percent to 41 percent. A deep animus toward China, amplified by misinformation in Vietnamese-language media, bolsters the support for a president they see as tougher on foreign policy. This dovetailed with their anticommunism.
My school (UK, 1980s) offered Mandarin as an extracurricular course. I signed up, showed up… and was the only student. One-on-one classes the rest of the year :)
(Just don’t try grilling me in Mandarin now, though.)