Al-Qaeda and the Islamic State of Iraq and the Levant (ISIL, also known as ISIS) have always considered "the West" - and the United States in particular - the ultimate enemy.
But following President Vladimir Putin's policy of military involvement in Syria, Russia may have taken its place as ISIL's main target.
"At the moment ISIL's rage is directed at Bashar al-Assad and Putin.They are the main enemies of ISIL because Russia has smashed ISIL in Syria and the same in Iraq. They will do anything to get their revenge on Russia," says Ahmad Saeedi, Dawat University, Kabul.
Thousands of ISIL fighters from Syria, Iraq and elsewhere are regrouping in the virtually impregnable mountains of Afghanistan, plotting revenge against the Kremlin.
ISIL's high command have given orders to target Russian cities, with thousands of trained fighters ready to act at any time.
