His activities in underground defense began during the Arab riots of 1936--1939, when he served under Yizhak Sadeh in the special units of the Haganah.

In 1941 he was among the founders of the Palmah, the crack commando unit of the Haganah; he became its commander in 1945. During the War of Independence he commanded decisive operations in all parts of the country, and in the final stages of the War he commanded the southern front, driving the invading Arab armies from the whole of the Negev, including Eilat and part of the Sinai peninsula. He came to be regarded as the most experienced field commander in the Israel Defense Forces and left his stamp on the standards that characterize Israel's army officers.

After the War of Independence, he studied at the Hebrew University and at Oxford. Turning his attention to political activity, he became one of the leaders of the Ahdut ha-Avodah political party, and in 1954 was elected to the Knesset.

From 1961 to 1968 he served as minister of labor, where he improved the state employment service, extended the road network and introduced legislation on labor relations. In June, 1967, he was a member of the inner war cabinet that mapped out the Six-Day War strategy. In 1968 Allon became deputy prime minister, and in the following year became minister of education and culture as well.

According to Allon's ideas on a peace settlement with Israel's neighbors, Judea and Samaria should be reunited with Jordan, but no Jordanian troops should be permitted to cross the Jordan River westward, and there should be a protective belt of Israel settlements along the Jordan Valley. From 1974 to 1977 Allon was Foreign Minister of Israel while retaining the deputy premiership.