Critiquing Israel as well as any political or religious entity or set of beliefs should be allowed, or there will be problems. This is basically the Paradox of Tolerance coupled with the fact that intolerance itself seems to be a viral meme if left unchecked.

I still can't believe the UK has arrested people based on their social media posts. Why are people standing for that, over there? (I'm a US citizen.) Meanwhile, one could make direct quotes from the Quran or Hadith and you'd likely remain unchallenged because religion gets a free pass from reasonable critique for some illogical reason. Appeasement will eventually lead to fear...