The UN General Assembly which did not and still doesn't have the power to make decisions, that power being reserved to the Security Council, voted to partition the remaining area of the British Mandate into two states on November 29, 1947, one Jewish and one Arab, but that did not create the state. That was done unilaterally by David Ben-Gurion on May 14, 1948 after the British speeded up their scheduled August departure and pulled their troops out of Palestine. The newly declared state was recognized by Truman, de facto right away but not de jure until January 31, 1949. The USSR was the first to recognize it de jure. UN membership came later. What is rarely mentioned is that the Security Council chose not to act on the General Assembly vote. November 29, 1947, is memorialized by Palestinians and their supporters because of the UN partition vote but, in fact, it had no legal standing and the Jews in Palestine would have done what they did to the Palestinians if the UN had not existed. They had already begun the ethnic cleansing before that with the massacre at Deir Yassin on April 8, being just one example.