I’m trying to work out why the US is sending an arms package to Israel.

Because, despite the hundreds of billions in murder-toy allowance the US has given Israel, the Palestinians have pretty much proved with this latest attack that it's not enough to secure the normalization of the kapo regime's existence.

I'm getting Tet offensive vibes from all this... and the fact that the US is quickly shoving large naval units into the area just strengthens it.