Earlier quoted context omitted.
This is the other thing: the US backed Israel because Israel was strong; Israel was not strong because the US backed them. At the end of the mandate period, Israel was the only country in the region with a real military, because the UK had just spent the last decade training and arming that military. At the time, the US was virulently antisemitic (see McCarthy era stuff for examples), as was most of europe.
Any sources for that claim? That's a super complicated issue and saying "because Israel strong!" seems a bit simplistic to me.
Obviously, it's very complicated, but I think the basic picture of the middle east at the time is a bunch of states that were dysfunctional by design, with borders drawn up by powers like the UK who had the colonial modus operandi of creating states that were fraught with ethnic and sectarian tension, so these states would rely upon them for support.
When the mandatory period ended, the Israelis had two massive advantages: they had a classic, european style 'nation', not some post-colonial territory that had literally never worked as a nation ever; and they had an army that had been fighting a civil war against the palestinians for its whole existence, with british support and training. So it's not really surprising they win the first Arab-Israeli war. Then after that, they basically can build on this to secure more support and more weapons, and build stronger military institutions, etc.
[1]: https://www.brookings.edu/blog/markaz/2017/05/30/the-cias-ov...