Hizbollah has left the Lebanese government. Eleven members left the 30-minister government, just enough to bring it down and force a new one to be created. The UN's Special Tribunal for Lebanon (STL) has been looking into the 2005 assassination of Rafik Hariri for a while now, and is expected to hand down indictments soon - specifically, indictments involving Hizbollah. Saudi Arabia and Syria have been trying to keep the government together ahead of these indictments, but it looks like that's over now. Hizbollah is blaming that on the US, while they also try to thwart the STL.
At the moment, things do not look good in Lebanon. Once the expected indictments come out, Hizbollah and its allies are not going to be happy. The current situation arose when a power-sharing agreement was reached in November of 2009. But as Hizbollah was implicated in the Hariri assassination, things began to go downhill. Let's hope the situation doesn't disintegrate into violence.
More from the BBC.