i'm certainly not saying they should recognize the claim, i'm saying they should not kick the US off their land as a result of it. as long as that hurdle is cleared, i expect the countries to stay neutral in my expected war.
iran has plenty of prestige to gain. if they could defeat israel on the battlefield and at least force a better armistice, it would make it difficult for the pro-western governments in the region to survive. a significant amount of the population, especially in egypt and maybe jordan would want very much to join iran. also, what does iran have to lose? they lived with pretty heavy sanctions for quite a while, a land war in iran would probably be much more vietnam than iraq, they'd lean heavily on hamas and probably iraqi militias... i see nothing to lose and everything to gain.
russia has no bases around damascus and with how spread out and battle weary syria's forces are (or may be depending on how the remainder of the war goes), israel should have little problem encircling the city in virtually no time. also, israel has been attacking syria regularly and the US is on the ground in syria. russia wants its mediterranean bases, they waited until they were under threat before helping assad.
Having US airbases on their soil and buying US weapons isn't enough loyalty? But you are saying loyalty to US is better then representing the opinions and views of the countries and their inhabitants themselves just because Trump wants it? That's such crooked reasoning it hurts.... If any of the leaders of countries you named would vote to recognise the claim they would have riots in the streets and their jobs would seriously be in jeopardy.
They will not as there is to little to gain and way to much to lose.
I doubt Isreal will dare to fuck around in Syria, not while Russia is still an official ally of Syria.