I don't think I've ever seen in all of my wide understanding of history, such a tiny state successfully make an empire its vassal. Truly an astounding feat. It would be highly entertaining if it didn't bode poorly for humanity.
In part it's because they have the best intelligence apparatus in the world. I'm very impressed at how far above their weight they're punching.
I don’t agree with the assessment, but in terms of a great power being very interested in the interests of a small country, consider Serbia and Russia before WWI.
Really it comes down to religion, and Israel being the bastion of anti-islam in the Middle East. Doesn't hurt that they are also liberal democracy and have advanced economy as well.