this isn't about American citizens boycotting Isreal.

I already gave a longer response, but I want to do a TLDR:

This is entirely about Americans boycotting Israel. And expands it in several potentially dangerous ways.

Congress.gov summary:

Current law prohibits various actions by U.S. persons (individuals or entities) in relation to boycotts imposed by foreign governments on a country which is friendly to the United States and that is not itself the object of a U.S. boycott. This bill applies those prohibitions to similar boycotts imposed by IGOs.