Born in Iran, Mofaz immigrated in 1957 to Israel. Straight from high school he joined the IDF in 1966 and served in the Paratroop Brigade. He participated in the Six-Day War, Yom Kippur War, 1982 Lebanon War, and Operation Entebbe with the Paratroopers and Sayeret Matkal, an elite special forces unit.
Mofaz was then appointed an infantry brigade commander for the 1982 Lebanon War. Afterwards he attended the US Marine Corps Command and Staff College in Quantico, Virginia. On his return he was briefly appointed commander of the Officers School, before returning to active service as commander of the Paratroop Brigade in 1986.
Shaul Mofaz served in a series of senior military posts, having been promoted to the rank of Brigadier General (1988). In 1993 he was made commander of the IDF forces in the West Bank. In 1994 he was promoted to Major General, commanding the Southern Corps. His rapid rise continued, in 1997 Mofaz was appointed Deputy Chief of the General Staff and in 1998 he was appointed Chief of the General Staff.
His term of Chief of Staff was noted for financial and structural reforms of the Israeli Army. But the most significant event in his tenure was the eruption of the Second Intifada. The tough tactics undertaken by Mofaz drew widespread concern from the international community but were appriciated by the Israeli public as firm response against terror. Controversy erupted over the offensive in Jenin, intermittent raids in the Gaza Strip, and the continued isolation of Yasser Arafat.
In Israel, Mofaz conduct as Chief of Staff was considered positive. He sought the wave of violence coming early as 1999 and prepared the IDF for intense guerilla warfare in the territories. He fortified posts at the Gaza Strip and due to advance MOUT tactics and intelligent use of bulldozers he managed to keep IDF casualties low. However, he drew criticism for left groups because of the harsh methods he had undertaken (such as house demolitions).
In 2002 Shaul Mofaz was appointed defense minister after a government crisis by Ariel Sharon.
After retiering from the IDF, Mofaz joined the Likud party. Mofaz is a hardliner, although he supports an agreement with the Palestinians, he determined to "liqudize" Arafat and willing to make no compromise in the war against terrorist groups such as Hamas, Islamic Jihad and Al-Aqsa Martyrs Brigades. Due to his military experience, Mofaz believes the IDF can stop Palestinian terrorism.