You have been seriously misled.
You might be able to make a case that there is no nation of Palestine. Asserting there are no Palestinians displays the depth of your ignorance and gullibility.
In 1917 the Balfour Declaration stated:
His Majesty's government view with favour the establishment in Palestine of a national home for the Jewish people, and will use their best endeavours to facilitate the achievement of this object, it being clearly understood that nothing shall be done which may prejudice the civil and religious rights of existing non-Jewish communities in Palestine, or the rights and political status enjoyed by Jews in any other country.
The existing "non-jewish" people are Palestinians.
In 1948 Israel was created. It pleaded with the Arab inhabitants to stay and live side by side with them. The surrounding Arab nations demanded that Arab leave the new state and allow them to drive the Jews into the sea. Some left, some stayed, and eventually became citizens.
The new Jewish nation was immediately attacked by the surrounding Arab nations. As a result, Trans-Jordan occupied what is now known as the West Bank, and changed its name to Jordan, since the original name means across the Jordan, and now they occupied land west of the Jordan.
Over 600,000 Jews were forcibly exiled from the middle eastern Arab states, and Israel refused entrance of Arabs who had left Israel, hoping that Israel would be destroyed, and they would come back in and take over the Jewish property that had been built up over two millennium.
The 600,000 Jews resettled in Israel and elsewhere outside of the middle east. The Arabs, who had left their lands to give Arab armies a free hand in destroying Israel, were left by their fellow Arabs in refugee camps on Israel's borders. Jordan destroyed Jewish synagogues in Jerusalem, destroyed the Jewish graveyards, and use the tombstones as floors for their urinals. Access to holy sites was closed off to Jews. All Arabs living in the area, occupied by Trans-Jordan following the 1948 war, were given Jordanian citizenship.
In 1967 Israel begged Jordan not to attack Israel along with Syria and Egypt. Jordan attacked and as a result lost the West Bank to Israel, including occupied Jerusalem.
Jews now possessed the Temple Mount, which had been lost to them in 70 AD when Roman legions, destroyed Jerusalem. Since approximately 1000 BC, Jerusalem has been the capital of only one nation, Israel. All invaders Roman, Byzantine, Muslim, or Crusader never established any other nation on that soil with Jerusalem a its capital.
Jews, in respect for all religious groups, gave open access to all faiths to its holy sites, including the Mosque of Omar and the Dome of the Rock, on the Temple Mount.
The only group ever referred to as “Palestinians” prior to June 1967, were the Jewish settlers. Once Jerusalem and West Bank came into possession of the Jews (following a deliberate attack by Arab armies), a subgroup of Arabs had to be created, that would be viewed as a small, persecuted minority, rather than part of the greater whole of Arab Islam, and its final goal of the reestablishment if a Muslim Caliph, controlling all Muslim lands throughout the world.
Many leaders calling themselves the Mahdi have come and gone over the last 1382 years of Muslim rule, but all follow the same pattern of deception, brute force, enslavement, and subjugation of all peoples who do not bow to Mohammad and Islam. After all, the word Islam means submission.
There is no love exhibited by the moon god Allah, only forced submission. That god was worshiped in ancient Babylon, and by Mohammad's father, as an idol, before Mohammad used it as a unifying force for Arab expansionism.
Until the 1960s, ‘Palestinian’ meant ‘Jew’. I have seen Jewish IDs from the Mandate that said so. That’s why your example specified ‘non-Jewish communities’: If it had said ‘Palestinian’ it would have meant ‘Jewish’.
The citation does not define "Palestinians" as non-Jews. It refers to communities in a place called Palestine which are not Jewish, and therefore tacitly acknowledges that there were communities which were to be otherwise distinguished as Jewish; the "existing non-Jewish communities in Palestine" as opposed to existing Jewish ones. Were there no distinction to be made, the language would be as redundant as saying 'existing Palestinian communities in Palestine', or 'existing non-Jewish communities in non-Jewish lands'.
"Palestinian" is a geographical identification and "Jew" is not. To contrast the two is a sensible as comparing "Italians" to "people from the West Coast".
This statement in Balfour only informs us that there is a particular parcel land that is labeled "Palestine." It does not state any recognition of either a race or nationality of people called "Palestinians."
I have in my possession materials on Palestine dating back to 1845, when there were Jews in significant numbers already there, beginning to build railroads, establish institutes, becoming agriculturists, planting vineyards and orchards, preparing to develop that barren land into fruitful fields.
At that time they were "stealing" no land, but purchasing large tracts, and there was very little trouble between the Jews and the Arabs from surrounding countries (not "Palestinians").
Of course, the more they developed throughout the nineteenth century, and as Zionism was developing into recognizable organizations during the time that Americans were engaged in our own war between the States, the powers of Islam were also planning how they could use the Jews' ingenuity to a certain point in the development of Palestine, and then reconquer the land for Mohammedanism, and drive the Jews into the sea.
Eventually, the western press turned Zionism into a dirty word. If you read Zionist organs from 1875 to 1915, you do not read of hatred against any Arab inhabitants of Palestine. You read of plans and fund raising among Jews for the industrial and agricultural development of Palestine.
There were two movements of Jews with regard to a homeland : Hirschel's idea that a Jewish homeland was needed, but that it could be anywhere on earth ; and also the (e.g.) Chovevi Zion insistence that it must be in Palestine. Neither side of that issue wrote of ridding any place, no not even Palestine, of its then current inhabitants . . . which were, by the way, not in any kind of political possession of the territory any more than they are now !
There was no Palestinian nation and there was no Palestinian nationality.
If there was any development and higher learning there (and there was), it was by the finances and finesse of Jews, not Arabs.