I think you will find Hezbollah's key roll (Supported by the worlds key terror supporter Iran) is to secure and set up on Israel's boarder ready for a future strike on Israel. ISIS have interfered with this somewhat. Weaponry to them at times has come from Iran & Russia and under the radar, but not Israel's, hence Israel for years without notice takes out these supplies at times.
If Syria ever gets sorted, watch the next move onto the Golan Heights with Russia & Iran etc support, Huge oil reserves there and Iran's goal to wipe Israel off the map.
Hezbollah doing the hard mile - Yea right?