The other countries --Lebanon, Syria, and Iraq contributed very little military and did very little. It's like saying 30 countries fought with the U.S. in Afghanistan. Israel had soldiers who were citizens from from countries throughout the world. In 1947 there were people in that area who traced their families back for centuries and owned much of the land, either by deed or by having occupied it for centuries. Except for a brief number of years, there never was an Estonia or an Estonian people; after WWI, the League if Nations recognized that those who lived there for centuries and spoke the same language were a nation and deserved the land. Same with the Palestinians. During the Mandate, the British called them Palestinians. There is no Israel state; Israel has no defined borders and citizens have an ethnic nationality and not an Israeli nationality. Israel, and not any Arabs have made it that way. You should be asking, why is there a land inhabited by foreigners who steal land and oppress those that previously owned the land and want their own state?