Part of the study of geography is the inclusion of different aspects of each country, one of them being the flag. If I had a room dedicated to the study of geography, you can bet your Stars and Stripes I'd have flags displayed from each of the countries we were studying...year round. However, they would be around the room, the American flag would hang front and center.
This is stupid! The principle needs an education.
I actually agree with everything you said except that the principal needs an education.
It is a state law that the principal was enforcing. I don't know why the legislature and governor enacted the law but they did.
The principal gave the teacher a chance to remove them until such time that they are allowed under that law and he wouldn't. I take it that the teacher has an agenda other than the education of his students.
I find it suspicious that the two flags the teacher had displayed and wouldn't remove were Mexico and China. They're both hot button issues in our country at present.
That's just my take on it.