Easy. You stop using "protecting culture" as a racist dog whistle. You protecting culture by preserving landmarks, education, helping families survive economically, having festivals and national support. You don't do it by deliberately targeting people based on race or race-adjacent qualities. BTW most racism in the world has DECIMATED native culture. Including Japan, with the Ainu.

I draw the line when you start deliberately targeting people to exclude on the basis of their race or culture.

Also, preventing other people from experiencing a culture does not protect it.

So, in order to protect culture you can't share it? Seems silly.