Nasrallah is a Shiite, ISIS is Sunni - they hate each other - Nasrallah is fighting with Iran and Russia in Syria against all of the Sunni groups of which ISIS is the largest.
Nasrallah and ISIS both are ememies of Israel and both are on or near the Golan.
“Nasrallah and ISIS both are ememies of Israel and both are on or near the Golan.”
Some enemies are more enemies than others. Israel clearly fears the more organized Perso-Russian-Secular-Shittes than they fear barbaric horde of 7th century Arabo-Sunni-Turko-ISIS camel fkers.