Hezbullah is a member of the governing coalition of Lebanon. Which is why Israel is holding Lebanon responsible for the actions of Hezbullah and is considering Hezbullah's actions as an act of war. Acting as a state within a state isn't going to give Hezbullah any cover when it comes to Israeli retaliation. And the Lebanese as a whole will suffer the consequences of allowing Hezbullah to behave as if it were a state within a state.
But the real power pulling the strings here is Iran which controls Hezbullah (Interesting to note that Syria and Iran recently
signed defence treaty). And if those 2 captured soldiers are ever transfered to Iran, well your guess is as good as mine.