Read more of Slate’s coverage of the Libyan protests.

After more than 40 years in power, is the Great Socialist People’s Libyan Arab Jamahiriya, as Muammar Qaddafi’s government is known, at its end? News from Libya is fragmentary and at times contradictory, but all signs point to a regime in crisis. Benghazi, Libya’s second-largest city, is in the hands of the demonstrators, who are gleefully shouting anti-regime slogans. Tripoli, the capital, is in chaos, with buildings on fire and the police in hiding. Key military units are defecting, while once-loyal tribal figures and political elites are condemning the regime.

It’s not over. In a speech on Sunday, Qaddafi’s son and presumed dauphin, Saif al-Islam Qaddafi, declared that “We are not Tunisia or Egypt,” and warned, “We will fight to the last minute, until the last bullet.” Previously, Saif’s role has been to present a respectable face of the regime to Western audiences, usually mouthing slogans about human rights and civil society. In other words, he’s the nice one. So if he’s warning of hell to come, believe that the regime means it.

Indeed, Libya already seems to be descending into a civil war. Hundreds have died as the regime has mowed down demonstrators. How many are dead is impossible to tell, because the regime has imposed a media blackout and tried to restrict cell phone and Internet access. But clearly this regime does not plan to go gently.

A key question is whether the Qaddafi family can ensure the loyalty of the important tribes and military figures that have not yet declared for the opposition. The defections so far are encouraging signs that Qaddafi is failing. Justice Minister Mustapha Abdul Jalil reportedly condemned the regime because of its “excessive use of violence,” and various ambassadors have apparently abandoned Qaddafi. While these individuals may truly be appalled by the bloodshed, you do not rise in Qaddafi’s government if you suffer from excess morality. So their departure suggests that these key insiders believe the regime’s days are numbered, and self-interest is driving them to desert the sinking ship.

Just as the regime struggles to unify to stay in power, so must the opposition if it is to end this tyranny. Qaddafi divided and ruled as well as coerced and co-opted, so Libyans are not used to working together politically. In Egypt and Tunisia, the militaries had a sense of institutional pride, and hatred of the regime kept disparate forces working together. The Libyan military is far more politicized. Moreover, Libya has historically had less of a sense of national unity, making it harder for people in Benghazi to coordinate their activities with those in far-away Tripoli. Even more important, so far the regime has fought back hard—and for the most part its outrages have been shielded from the scrutiny of the international media.

The opposition must stay united to prevent the regime from rallying its forces and defeating them piecemeal. For while the demonstrators have the numbers, Qaddafi loyalists (for now at least) have the guns. If military defections become widespread, the balance of force will change. But too often in the Middle East a small but well-armed few has imposed its views on the many.

Unlike in Egypt or Tunisia in the last weeks, or today in Bahrain—where peaceful demonstrators are trying to change their government—the Obama administration has a disadvantage in Libya: a lack of influence. In Egypt, the close relationship between the U.S. and Egyptian militaries, to say nothing of the more than $1 billion in aid every year, gave the Obama administration a say in events there. Bahrain is a close U.S. ally, and Washington is also close to Saudi Arabia, Bahrain’s neighborhood big brother. In Libya, on the other hand, the United States has little or no ability to sway the regime. Denouncing Qaddafi means little, and there is no aid or serious cooperation to withhold.

This disadvantage, of course, comes with a blessing: Libya is not a close U.S. ally. While Libya is an important oil producer, and while it does assist U.S. counterterrorism efforts against al-Qaida and its allies, the decades of hostility and the bizarre nature of Qaddafi’s rule have limited the rapprochement that has occurred in the last decade or so.

So while policymakers worry that a post-Mubarak Egypt or a democratic Bahrain may be more hostile to the United States, in Libya there is a sense that a new regime can’t be any worse. That is always dangerous thinking in the Middle East, where bad regimes were often succeeded by worse ones. The chaos in Libya and the lack of unity among the opposition also raise the risk that strife could become a sustained civil war, with thousands more dying. For now, however, it seems right to hope that Libya will follow Egypt and Tunisia, even though there is little the United States can do to make this happen.

Like Slate on Facebook. Follow Slate and the Slate Foreign Desk on Twitter.