The Arab–Israeli conflict involves political tension, military conflicts, and other disputes between Arab countries and Israel, which escalated during the 20th century, but had mostly faded out by the early 21st century. The roots of the Arab–Israeli conflict have been attributed to the support by Arab League member countries for the Palestinians, a fellow League member, in the ongoing Israeli–Palestinian conflict, which in turn has been attributed to the simultaneous rise of Zionism and Arab nationalism towards the end of the 19th century, though the two national movements had not clashed until the 1920s.
Part of the Palestine–Israel conflict arose from the conflicting claims by these movements to the land that formed the British Mandatory Palestine, which was regarded by the Jewish people as their ancestral homeland, while at the same time it was regarded by the Pan-Arab movement as historically and currently belonging to the Arab Palestinians, and in the Pan-Islamic context, as Muslim lands. The sectarian conflict within the British Mandate territory between Palestinian Jews and Arabs escalated into a full-scale Palestinian civil war in 1947.