I was surprised to see this open letter to Walter Block from Hans Hoppe that is essentially revoking his libertarian card over Block's position on Israel.
I haven't followed either figure closely in recent years. but I credit both men with playing an important role in my intellectual journey and they are major figures in the post-Rothbard libertarian intellectual tradition.
The crux of the disagreement is Block's collectivist arguments on behalf of Israel and against the Palestinians. I haven't read Block's articles in full, so I somewhat reserve judgement, but I fully agree with the arguments as laid out by Hoppe in the letter.