three of his brothers-in-law were Nazis
The Windsors had a real blind spot when it came to the Nazis. Some of it was due to heritage. Some of it was due to what happened to the czar and his family and their role in it. Some of it was just outright anti-Semitism.
But the British monarchy stopped being about what’s best for their subjects centuries ago, so in that respect the Windsors are carrying on a fine tradition of doing what’s best for them.