Then no one can claim any total differance since every group has common similarities. French and Italians are the same they are both descended from Latin but the local dialects diverged.
Except in case of Arab world, we aren't talking about having similar language a thousand years ago but diverging since then, they didn't, it's still the same language, at worst with an equivalent of bad Scottish or Australian dialect for English speakers as far as being hard to understand goes.
I'm not an expert in middle eastern peoples, but if you are making the claim that they are all one people why haven't they joined together?
Why haven't North Korea and South Korea joined together despite actually being one people?
Politics.
Assads like their power, Hashemites like their power, lots of tribalisms, Gulf States not wanting to share their oil money nor to be conquered out of their oil money etc.
If they were ever to become easygoing populist democracies and tell all the islamist influencers causing incidental and intentional divisions between them to sod off, we could see some of them uniting.
And Israel did not exist till 1948. No you don't have to have a state to be a nation, jews were a nation for thousands of years even if they did not have a country. To be a nation you have to be a group of people with a common culture that thinks of yourself as one people.
So far so good.
The Palastinians see themselves as Palastinian, the Egyptians see themselves as Egyptian.
And here you are blindly projecting the European post-Westphalian order upon people who don't know it and don't care about it.
Look up the quotes of notable leaders from Syria and Palestine i brought up earlier. Also look up the sheer amount of lobbying and fighting the Arab states did for the "Palestinian cause" - would totally foreign people put so much effort into some other nation they don't give a damn about?
Did Hafez Assad get yelled at by Palestinians for denying their existence as a nation to Arafat's face and claiming they are just Syrians?
No what makes a nation is many things, language, culture, history, religion, and of course blood/genetics. The Czech's and Slovaks were two diffrent people in one nation.
But they don't consider themselves one nation, that's why they split. They are two nations formerly squeezed into a greater polity. The reverse is also possible, like the split of Korea or earlier, Germany.
What differances do they have that are not based on religion? Do they eat diffrent foods, look diffrent? Again the only differance is that they are the minority who remained true to their faith while the rest of the Egyptians bent over for the Arab conqurors. But the genetics connection of the common Egyptian are just the same like the genetics connection of the modern Greek to their ancestors. If modern Egyptians decided to reject Arab imposition there would truly be no differance between the Copts, and the majority Egyptian except religion.
Then you are just simply uninformed. Religion is just the surface, somewhat different culture with socioeconomic differences follows, then there is language (Coptic vs Egyptian Arabic), and to some degree genetics - 23andme even separates Egyptian and Coptic Egyptian.
What are the real differances between Austria and Germany?
Why should they be a separate people?
Politics, that's what a certain mustachioed gentleman who died in a bunker asked.
You could say history, but wouldn't actually be right because Germany is a modern artifical creation of all the German states, (led by Prussia) Those states have a similar history to Austria. Austria was not brought into a German empire because they were Catholic and too big too absorb by mostly protestant Germany(except Bavaria). But now there is no differance both states are Secular, modern Germany does not enforce or favor Protestantism. And modern Austria does not enforce Catholic laws, or favor the Catholic Church above others. What makes them diffrent? They both speak German, they both have similar clothes, music, food, beer, customs. What seperates them but religion?
Even religion, being western European many there don't care much anymore. But historical heritage does separate them somewhat, Kaiserreich vs Austro-Hungary, with some underlying cultural differences to follow, like Austria having looser anti smoking laws enforcement.
I said earlier it does, that stuff does matter but only if there is a differance like there are two similar groups but they seperate themselves based on those things, but tell me Marduk you are Polish. If a Polish person stops being Catholic and instead becomes a Muslim, a Jew, Buddhis, or atheist do you think they lost their Polishness? Is adherence to Catholicism like most Poles have a requirement to be a Pole?
No. But as i said it's not a matter of one factor, it's really a compound of many. If a Polish person becomes a Muslim, starts talking Arabic, starts dressing like a Bedouin, and declares his loyalty to some caliph over infidel governments, then for practical purposes, how is he Polish anymore?
Not myth,reality.Medieval Russians were not genociders,like soviets.They do not killed Chazars.Some jews come there from East,but rest - they were Chazars.
And later run to polish territories,when Ivan terrible covard start murdering jews on his lands.
en.wikipedia.org
en.wikipedia.org
Of all people you should know better.