I have a hard time imagining a Lockheed plant being bombed

We are at least one generation away from something like that happening. Probably more. It will happen eventually, but until it does nothing will come of these protests.

Theoretically they can, I don't know how that would work out in practice though.

I think they're a big exporter of diamonds.

The Diamond industry of Israel is an important world player in producing cut diamonds for wholesale. In 2010, Israel became the chair of the Kimberley Process Certification Scheme. As of 2016, cut diamonds constituted 23.2% of Israel's total exports and they were the country's biggest export product, amounting to 12% of the world's production.

The U.S. doesn't have enough to keep an entire nation floating for free.

Don't get me wrong they will sink billions upon billions (hundreds) making sure it doesn't collapse but it can't survive directly on U.S. support alone. If international capital is scared of doing things in Israel, there's only so much the U.S. can do I think.