The violence rapidly escalated and the country descended into civil war. Hundreds of rebel groups sprung up and it did not take long for the conflict to become more than a battle between Syrians for or against Mr Assad. Foreign powers began to take sides, sending money, weaponry and fighters, and as the chaos worsened extremist jihadist organisations with their own aims, such as the Islamic State (IS) group and al-Qaeda, became involved. That deepened concern among the international community who saw them as a major threat.
