Jordan (formerly Transjordan) is the Arab state carved out of the British Mandate of Palestine after the collapse of the Ottoman Empire.
You say that like it's supposed to mean something. Similar would be the US declaring the state for the Sioux/Iroquois/Mandan to be in Canada or Mexico.
The rest was designated as a Jewish homeland
Which no one had any business doing, as said Jews have no more ties to Palestine than you or I do to a slice of China if we convert to Confucianism. They are Europeans who converted to another religion. No different to how Latin America was (forcibly) converted to Catholicism. Doesn't mean they have a slice of Palestine as that's where Christianity also comes from.
Of course, every other party of the Ottoman Empire except Turkey itself is also now an Arab state.
You also say that like its supposed to mean something. Is it okay if all the Palestinian refugees - millions of them forced out by Israel - invade and cleanse Delaware of Americans because "so many other 49 American states?"
All you have to do to show the absurdity of Zionism by keeping the same reasoning but changing the variables.
In the 1948 Arab-Israeli war, one day after the modern state of Israel was created, it was invaded by the combined armies of Egypt, Jordan, Syria, Iraq, Lebanon, Saudi Arabia, and Yemen.
After better part of 750,0000 Palestinians were forced out of their own homes into said neighboring countries. Weird, how you expect "Israel's" neighbors to use their own land and resources to support your colonialism with zero compensation. Almost like you're a racist clown show.