I have never really understood why you can't criticize Israeli politics without it sounding like antisemitism.
-Israel is an apartheid state.
-You fucking nazi!
But to answer your question: There are a TON of antisemitic people in the world, but they know they can't talk that way, so they pretend that are "anti-Israel" instead. Most people can see right through that, some can't.
This doesn't happen to other countries, so the situation with Israel is unique.