This is a part that's often overlooked, but there is a lot more context to it.That's pretty much the history of anyone who takes in a lot of Palestinians.
Jordan took in all of westbank and gave them full rights as Jordanians and seats in parliament. Palestinians then decided they could take over the nation by claiming Jordan was also part of Palestine and tried to have an insurrection and overthrow the monarchy. Which lead to black september. Jordan started shelling the fuck out of the fedayeen(Early hamas militant types)who were embedded with civilians and killed 25000 palestinians until they fucked off to and were allowed in lebanon.
Which fucked over Lebanon, which was at the time a multicultural place, but the balance shifted to islamic militants majority(and they had a civil war a few years later due to the palestinians arriving)
Etc etc
This is a history that repeats itself with Palestinians and the main reason everyone will say "awww, let me send you money and aid.....but stay the fuck out of my country"
Egypt built a wall and flooded nd shelled Palestinian tunnels with them in them to keep them the fuck out
1. Palestinians feel (rightly or wrongly) that they have some claim to Jordan in a way which they do not to the United States. It's a reach to see Jordan and argue that they would do the same in the US, like many in this thread are arguing. Palestinians aren't born with some innate trait that makes them want to take over countries.
2. Most of the Middle Eastern countries mostly care about Palestine as a political cudgel rather than an issue to be solved. It's a nice distraction from their own failings that shores up some religious blocs for money that most have plenty of.