In the name of Allah, defense Jihad is obligatory in any case, and that is why we have ordered the Shiites of Ali (PBUH) to go to the battlefield to defend Iraq of Islam, Iraq of Ali and Hussein (PBUH). As for the starting (commencing) jihad for spreading Islam, it is conditional on the permission of the Awaited Imam (may Allah hasten his reappearance) or his deputy regarding jihad or something more general. Allah knows best.