After World War II and the Holocaust, more Jewish people wanted their own country. The Jewish people were given a portion of the country, Palestine. The Jewish population had already considered their traditional homeland, but the Arabs that lived there and in the surrounding countries thought that was unfair and refused to accept the new country.
At first the immigration was no problem, but the movement and rapid immigration of Zionists into Palestine, conflict soon broke between the Palestinians and the Zionists.
In 1947, the UN decided to intervene. Instead of allowing the people to decide the land splits, and create their own state and government, the UN did it for them.
Under Zionist pressure, the UN recommended giving away 55% of the land to the Jewish state. Only 30 % of the population and 7% of land owned in this 55% was Jewish.
750,000 Palestinians had been made refugees and every river, town, and hill had been changed to a Hebrew name to virtually eradicate all Palestinian culture. Israel's prime minister even denied the existence of Palestine.
I do believe that nationalism is a factor in global conflicts because its been proven with Germany in WWII, Europe in WWI, and in Palestine before the movements of the radical Zionists.