The Lebanese Army et al.
First the ability. I am skeptical that the Lebanese army can take on the Hezbolalahs. They are proving to be a tough foe and most Arab national armies seem only to be competent against unarmed citizenry. The Hezbolalahs I think would be able to take on the Lebanese army.
However, the more important questions are about Lebanon's will. Even tough Syria is officially out of Lebanon it still wields considerable influence in Beruit also the Hezbolalahs much like the Nazis are playing the political game as well and are in the Lebanese government.
Unfortunately the easy solutions for Lebanon's problems passed six years ago and they were in an even more compromised position than they are now. Lebanon is truly the parasite infested mutant frog I portrayed it some weeks ago.