 After his release he became an assistant of Salah Shehadeh and Mohamed Aldahef, the commanders of the military wing, in charge with improvement of military actions.Thus, he was part of Hamas's high-ranking military leadership during the first intifada and of the first Intifada cell.On 26 September 2002, after an Israeli airstrike wounded Mohammed Deif, the leader of Hamas's principal armed wing, the Izz al-Din al-Qassam Brigades, Jabari became the commander and operational head of the military wing at the height of the Second Intifada (the armed Palestinian uprising against Israel from 2000–2007).