A conversation stopper can be the accusation that any criticism of Israel is antisemitic.
Richard Gold tackles this issue with a piece entitled “How to criticise Israel without being antisemitic”
The well worth reading piece is here
Gold provides 19 rules; some of which are fairly standard e.g. Don’t claim that the Jews control the media/banks/country that isn’t Israel.. and others such as Don’t say “the Jews” when you mean Israel.