I think they’ve majorly underestimated how much the world is going to condemn this. It was one thing to “protect it’s citizens”, it’s another thing entirely to outright invade another nation.

I think you’re majorly overestimating how much the world cares.

Israel has been invading other nations literally continuously throughout its existence. You can debate that it is to “protect it’s citizens”, and there may even be some truth to that sometimes, but it’s clearly generally been the aggressor since its founding. And (almost) nobody cared.

I’d be shocked if Europe doesn’t sanction Israel

Some strong-worded letters will surely be sent, and politicians will call on “all sides to stop the hostilities”, which in practice means Israel gets to keep whatever it could occupy. Maybe a couple of somewhat left-leaning countries (Spain, Sweden, Norway, etc) will sanction Israel individually, but then they don’t have much trade by this point anyway so they have no negotiating power. As for the rest, trading (including trading weapons) with Israel is profitable monetarily and beneficial politically, so not much will really change.