NATO sent a message to Libyan leader Muammar Qaddafi early this morning about its resolve to protect civilians and break an apparent stalemate, and it did so through what the AP is calling the coalition's "most intense bombardment yet" against Qaddafi's base in Tripoli. setting off more than 20 explosions in rapid succession near Qaddafi's Bab al-Aziziya compound. Libyan government spokesman Moussa Ibrahim said the airstrikes hit buildings used by Libyan army volunteers and killed at least three civilians, but NATO claims it targeted a military vehicle depot that the regime was using as part of its attacks on civilians. The Twitter user @ChangeInLibya has posted the incredible photo above of the sky over Tripoli during the attacks. The BBC also has dramatic video of the airstrikes (warning: some images, about 30 seconds in, may be disturbing):

The stepped-up military campaign isn't just coming in the form of massive airstrikes. As The Telegraph reports this morning, the French and British have decided to dispatch 18 Apache helicopters with support from Special Forces Troops, in a move the paper says takes the "allies closer still to a full ground operation in Libya." The low-flying helicopters, which are used in Afghanistan to target militants and which can deploy their missiles and cannon more precisely, will help the rebels consolidate their control over the besieged city of Misrata and target mortar batteries, military vehicles, and Libyan snipers and commanders, according to The Telegraph. But, as the AP points out, the helicopters are also vulnerable to ground fire, and NATO has avoided military deaths in Libya so far.

Several news reports today also suggest that there is significant movement on the diplomatic front. U.S. Assistant Secretary of State Jeffrey Feltman, the most senior U.S. diplomat to visit the eastern rebel stronghold of Benghazi, announced on Tuesday that the Libyan opposition will open a representative office in Washington, DC (the rebels are also opening an office in Paris). Jordan, meanwhile, formally recognized the rebels' National Transitional Council (NTC) as the legitimate representative of the Libyan people--a move the U.S. has yet to do because, in Feltman's words, the NTC's "job is to go out of business" when Qaddafi is ousted. And Russia has recognized the TNC as a legitimate negotiator on Libya's future, according to Ria Novosti. On Monday, Senate Democrats and Republicans introduced a resolution calling for limited U.S. military intervention in Libya and recommending that the U.S. give the Libyan people the regime's frozen assets. The resolution also stated that the goal of U.S. policy in Libya is to "achieve the departure from power of Muammar Qaddafi and his family."