According to YOU the brits GAVE it to the UN.
According to history.
Not even close. After WWI, the League of Nations took control of the area known as Palestine, which included what became Jordan at that time, and established the Mandate for Palestine, naming Britain the Mandatory Authority but operating under the auspices of the League, with the explicit instructions:
"Whereas the Principal Allied Powers have agreed, for the purpose of giving effect to the provisions of
Article 22 of the Covenant of the League of Nations, to entrust to a Mandatory selected by the said Powers the administration of the territory of Palestine, which formerly belonged to the Turkish Empire, within such boundaries as may be fixed by them; and
"Whereas the Principal Allied Powers have also agreed that the Mandatory should be responsible for putting into effect the
declaration originally made on November 2nd, 1917, by the Government of His Britannic Majesty, and adopted by the said Powers, in favor of the establishment in Palestine of a national home for the Jewish people, it being clearly understood that nothing should be done which might 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; and
Whereas recognition has thereby been given to the historical connection of the Jewish people with Palestine and to the grounds for reconstituting their national home in that country; and
Whereas the Principal Allied Powers have selected His Britannic Majesty as the Mandatory for Palestine; and
Whereas the mandate in respect of Palestine has been formulated in the following terms and submitted to the Council of the League for approval; and
Whereas His Britannic Majesty has accepted the mandate in respect of Palestine and undertaken to exercise it on behalf of the League of Nations in conformity with the following provisions; and
Whereas by the afore-mentioned
Article 22 (paragraph 8), it is provided that the degree of authority, control or administration to be exercised by the Mandatory, not having been previously agreed upon by the Members of the League, shall be explicitly defined by the Council of the League Of Nations;
confirming the said Mandate, defines its terms as follows:"
The Avalon Project : The Palestine Mandate
In other words when Britain accepted the role of Mandatory from the League of Nations, it agreed to establish a homeland for the Jews in the area then known as Palestine.
After WWII the unfinished business of the now defunct League of Nations was transferred to the newly formed United Nations under the same provisions as before, and a few years later Britain withdrew from its role as Mandatory and the UNGA decided to dissolve the Mandate with resolution 181 which recommended the formation of two states but did nothing to implement it. With the withdrawal of the British, Israel declared its statehood, which was recognized by the US and USSR and some other countries but not by Britain or the UN, the Arabs attacked and were beaten back and in 1949 the UN offered to recognize Israel and admit it as a member nation if it stopped pursuing the fleeing Arab armies, and accepted a truce and Israel accepted.
So while the League of Nations, Britain and the UN had all promised to establish a national homeland for the Jewish people in the area then known as Palestine, it was the Jews living there at the time who did, in fact, create and establish the state of Israel, the national homeland of the Jewish people, without any help from the UN or from Britain.
That is the history.