If you think about it federalism is obviously not a good option in Iraq for the US because Iran would definitely get the upper hand. However, in the Lebanese case, it is the only option if the US hopes to keep some king of political leverage (especially when possibly working out the resolution of the Israeli-Palestinian conflict). The US would prefer either a federal Lebanon or one where Hizbullah is neutralized. This is why the 14th of March is definitely the best thing the US can have. Two of its leaders won’t mind having the country broken up. Actually federalism for Samir Geagea and Walid Jumblatt is one of the best way to have more political leverage. Even Mustaqbal leader Saad Hariri wouldn’t mind and will accept US demands to naturalize the Palestinians. Decentralization (even compartmentalization) works best for feudal and other elites and oligarchs who don’t have the popularity that elites have on a national scale. Geagea and Jumblatt also come from a deep seated culture that political cantons is the most efficient system (in which they enjoyed much more privileges (recall the civil war) economically and politiclaly then in a coalition).
Now although Hizbullah comes from the working of one canton, it does not have the federalist culture. This is important to understand. Hizbullah started working from a micro-setting and moved slowly to nation-wide goals (it still has to prove itself on so many issues of course). All the institutions Hizbullah has created (hospitals schools, construction, social assistance etc.) do not work with a civil-war-militia-mindset (these institutions are available to anyone). Also Hizbullah has come into existence because of an occupation problem that the State of Lebanon was too weak to address (and also because the regional situation did not let the State address the issue independently). So Hizbullah fought for a national cause. For Hizbullah, federalism is obviously not a first option.
But but but.. I would not be surprised to see Hizbullah say: “well if this is what you want, we’ll manage”. What I mean is, Hizbullah won’t be with federalism because it really doesn’t need this option to keep the course, but at the same time, it will be ready to work with it, if federalism is just inevitable. Hizbullah stands to gain in every way from a coalition government, but will probably not lose that much if it falls back on the non-state institutions it has in place (although it will be much more isolated, and sandwiched between Israel and a pro-US puppet government, so it will still loose more). The only party that will be the biggest loser in a federal structure the Aounist (Tayyar). Tayyar’s constituency spreads on different parts of Lebanon. And this is why Tayyar’s alliance with Hizbullah is the most important political phenomenon since Fouad Chehab’s mandate. And it works in the interest of Hizbullah whose only way to go from a non-state to a full national party is through such types of coalitions.