Following the war, Ben-Gurion served as Israel's first Prime Minister. As Prime Minister, he helped build the state institutions, presiding over various national projects aimed at the development of the country. He also oversaw the absorption of vast numbers of Jews from all over the world. In 1954, he resigned and served as Defense Minister, before returning to office in 1955. Under his leadership, Israel responded aggressively to Arab guerilla attacks, and in 1956, invaded Egypt along with British and French forces after Egypt nationalized the Suez Canal. He stepped down from office in 1963, and retired from political life in 1970. He then moved to Sde Boker, a kibbutz in the Negev desert, where he lived until his death. Posthumously, Ben-Gurion was named one of Time magazine's 100 Most Important People of the 20th Century.