Ya'alon (born June 24, 1950) was born as Moshe Smilansky in the Haifa suburb of Kiryat Haim. In his youth, Smilansky became active in the Labor Zionist movement and joined a pioneer group named Ya'alon, which he would later adopt as his name. In 1968, Ya'alon was drafted into the Israel Defense Forces and served in the Nahal Infantry Brigade until his discharge in 1971.
During the 1973 Yom Kippur War, Ya'alon served as a reservist and participated in the liberation of the Suez Canal. He returned to active service after the war, completed officer's training school and commanded units in the Paratroopers Brigade as well as the elite special forces unit Sayeret Matkal, where he led the 1978 Litani operation and fought in Operation Peace for Galilee. He rose to become deputy commander of the IDF Paratroop Brigade and near the end of his term, he was wounded in Lebanon.
In 1986, Ya'alon left to pursue advanced studies at the command and staff college in Kimberly, England. When he returned to Israel, he became deputy commander of the elite unit in which he had previously served. From 1989 to 1990, he retrained in the IDF Armored Corps and completed a BA in Political Science at the University of Haifa. In February 1990, he was appointed commander of the IDF Paratroop Brigade and in January 1992, he was appointed OC Judea and Samaria and promoted to the rank of brigadier-general.
In August 1993, Ya'alon was appointed commander of the ground forces training facility at Tze'elim and commander of an armored division. In June 1995, he was appointed OC Intelligence and promoted to the rank of major-general. In May 1998, he was appointed OC Central Command. On September 15, 2000, he was appointed IDF Deputy Chief-of-Staff.
On July 9, 2002, Ya'alon was promoted to the rank of Lieutenant-General and appointed 17th Chief-of-Staff of the IDF. During his tenure as head of the armed forces, Ya'alon led the fight to secure Israel during the Second Intifada, instituting many battle practices that enabled the IDF to stop Palestinian terrorism. In February 2005, Defense Minister Shaul Mofaz announced that Ya'alon's position would not be extended, partly due to the latter's objection to the Gaza disengagement plan, and on June 1, 2005, Ya'alon retired from the IDF.
After leaving the IDF, Ya'alon spent time at the Washington Institute for Near East Policy and became a Senior Fellow with the Adelson Institute for Strategic Studies at the Shalem Center Institute for International and Middle East Studies.
On 17 November 2008, Ya'alon announced that he was joining the Likud Party and that he would participate in the primaries to determine the party list for the 2009 general elections. He won eighth place on the party's list and was later elected to the Knesset when Likud won 27 seats. Prime Minister Benjamin Netanyahu appointed Ya'alon as Vice Prime Minister (alongside Silvan Shalom) as well as Minister of Strategic Affairs.
Ya'alon was reelected to the Knesset in January 2013 again on the Likud ticket and in March 2013 he replaced Ehud Barak as Minister of Defense. He retained his position as Minister of Defense following the March 2015 election. Citing Netanyahu's “management in the latest developments,” and a “lack of faith” in the Prime Minister, Ya'alon resigned from the position of Minister of Defense on May 19, 2016. Ya'alon stated during a press conference that “senior politicians in the country have chosen incitement and divisiveness of the Israeli society instead of unifying and connecting.” During the weeks leading up to his resignation speculation was mounting that Netanyahu planned to replace him with Avigdor Lieberman, head of the ultranationalist Yisrael Beiteinu party, in order to increase his coalition's majority in the Knesset.
Moshe Ya'alon is married and the father of three children.