Comment by mirzap
Hezbollah is a legitimate political party in Lebanon, like it or not. This means that they have a lot of civilians involved in running a country. Just imagine Russia targeting pro-fascist AfD in Germany and justifying that by "fighting against fascism in Europe." There's 0 doubt everyone would see that as a state-sponsored terror attack and an attack on a German state - an act of war.
If AfD were firing rockets into Russia, Russia would have every right to retaliate.