Pan Islamism and solidarity among all Islamic nations have long been a pipe dream through out Islamic history. And this delusion carried itself further post 1950s as multiple nation-states that professes their allegiance to Islam were established. The Organization of Islamic Countries (OIC) was established with a vision of forming a bloc of Islamic nation that stretches from Morocco to South-east Asia that will counter the western, liberal influence on geo-politics. The reality, obviously, is far different. There never been pan Muslim solidarity throughout the history of Islam. And situation did not change at all despite establishment of OIC. And given the competing priorities of some of the strong (and some delusional) Islamic nations, one can safely bet that such unity will continue to be a pipe dream.
The issue of Israel is perplexing to most observer. It's been going on for so long that it's hard to remember what is it about to begin with. But the issue did serve its purpose for multiple state actors for decades. Under the guise of fighting with Israel, various Islamic nations of middle-east attempted to either spread their influence or straight up gobble additional geographic areas. For this blog's scope, let's ignore the Islamic nations of south-east Asia, Africa and Pakistan. That leaves us with key actors Iran, the immediate neighbors of Israel such as Syria, Lebanon, Jordan and Turkey and Saudi Arabia. Now, get ready for the whirlpool of competing priorities and messed up histories!
Saudi wants to assert itself as vanguard of Islam. That means taking up every issue - real or imagined, related Islam. Since Israel - a Jewish state is established literally at the heart of Islam's birthplace, Saudi's have to fight against them. Since they are too lazy to fight, they outsourced it to Hamas. But fight against Israel is rather secondary when it comes to priorities. The priority is to project Saudis are the only one steadfastly fighting against Israel and as the only true friends of Palestine. That's the important target. Because they do not want Persian (Iran) or Turkic (Turky) influence to grow in their backyard. The conflicting ethnicities of these three nations are to be paid attention here. Saudis are Arabs, Iranis are proud Persians and Turky is turkic.
This brings us to Iran - For Iranian theocracy to survive, they have to keep fighting the enemies of state - real or imagined. These enemies are Israel and US. Since US is too far for Iran showcase any 'fighting' spirit against, they have to make do with Israel. All the big and fervent rallies in Tehran aside, the reality is Iran do not posses any military capabilities to harm Israel. So Iran choose the Saudi way of outsourcing the fight. They support Hizbollah - another terrorist organizations. Iran funds them and ask them to die so that they can tell their domestic audience how Shia power is growing and how they are raining hellfire's on the Jews.
Since Saudis are Sunnis who hate Shias and Iran is Shias who hate Sunnis for Sunnis hating them, the fight between them, for all practical purposes, eternal. In fact, hate each other more than they hate Israel!
Now, Turkey is an interesting case here. They believe they are Europeans but they also believe they ought to own pretty much whole of middle-east since it once belonged to Ottoman empire once. And, also, and most importantly, they also believe all Islamic nations should bow to them since they were the last Caliphs. (The Caliphite was discontinued post WW 1 by Britishers. For some reason, Gandhi in India decided to start a moment - 'Khilafat' movement against this British decision.)
The only way Turkey can showcase their military chops , you guessed it right - is by going after Israel. For the records, modern day Turkey was not like this for last several decades. The emergence of Erodogan meant emergence of delusional self of Turkey. Now Turkey is not only meddling or trying to meddle with Israel but they want to be an actor in Syria / Lebanon conflict. They are openly siding with Pakistan against India. They are trying to play a role in Azerbaijan - Armenia conflict. They are all over! But this is what happens when one gets free money for years. Turkey has been one of the largest recipient of military aid from US for decades now.
Turkey not only considers their identity as Caliphs of Islam, which obviously puts them at odds with Saudi and Iran, but their Turkic ethnicity is increasingly becoming a focal point of their expansionist mindset. Turkey readily supporting Azarbaijan in recent skirmish between Armenia and Azarbaijan is an indicator of this new world view.
Iran is Persian, a proud one at that. Saudis are Arabs, a proud one at that too. So, not only Turkey is fighting with Saudi Arabs and Irani Persians for numero uno position in Islamic world, both Irani and Saudis are worried about ethnic Turks overpowering them again as Ottomans once did. All in all, it's excruciatingly confusing.
This brings us back to the recent development of UAE embracing Israel. For last several decades this anti-Israel mindset had a great hold over Islamic nation bloc's foreign policy. The first break in the rank was Egypt deciding to be cool with Israel in 1979 and then Jordan following the course in 1994. However, for next two decades the so called resistance in Palestine intensified further. Till the lull that happened in mid-later part of 2010's. As the realization that Palestine issue is no longer important to even Israel and the fact that Palestine is nothing but a pawn leveraged by external powers to serve their interest sets in, more Arab countries will join the bandwagon.
However, this does not mean the state actors, the self-proclaimed vanguard of Islam, will stop their attempt to establish hegemony. That will continue. It will only need a new enemy. And the whole cycle will begin again.