In 2011, Libyans revolted against the dictatorial rule of leader Mu’ammar Qaddafi. After initial successes by the rebels, Qaddafi’s forces began to reclaim control as they moved east along the coast. The prospect of a bloodbath in Benghazi, Libya’s second-largest city, spurred the international community to action. The UNSC passed a resolution authorizing member states to "take all necessary measures" to protect civilians in Libya, which allowed NATO to begin air operations and a naval blockade against Qaddafi’s forces. With NATO support, the rebels beat back the loyalists at Benghazi. Qaddafi was captured and killed two months later.

The Libya operation is an example of armed humanitarian intervention, the use of military force by outsiders to stop mass killing or genocide within a country. Other notable examples include the UN-sponsored intervention to relieve a famine caused by civil war in Somalia in 1991–93 and, on a smaller scale, U.S. air strikes against Syria in 2017 to punish the regime’s use of chemical weapons. The main argument for armed humanitarian intervention rests on the idea that everyone shares an interest in preventing suffering and death due to civil wars or murderous governments. But the practice remains controversial. Critics argue that (1) claims of humanitarianism disguise the self-interested reasons that actually motivate intervention, (2) military force is a poor instrument for influencing the strategic interaction between governments and civilians, and (3) existing institutions are not up to the task of deciding whether and when to intervene.

The case for armed humanitarian intervention rests on the moral imperative to protect unarmed civilians facing death at the hands of their government. When a state has failed in its basic obligation to protect its citizens from massacre, genocide, and other crimes against humanity, it has been argued that other states have a responsibility to intervene, by force if necessary (for more on the emergence of the "responsibility to protect" norm, see Chapter 11).

In the case of Libya, the looming attack on Benghazi reminded Western decision makers of their countries’ failure to act under similar circumstances in June 1995, when Serb forces overran the city of Srebrenica in Bosnia and massacred 8,000 men and boys. If given the chance to prevent another such atrocity, why not act? A policy of intervention can not only save lives that are at immediate risk, but may also deter governments from committing atrocities in the first place.

While this argument seems compelling, the uncomfortable fact is that most humanitarian crises do not trigger this kind of response. Genocidal killings in Rwanda (1994), in the Darfur region of Sudan (starting in 2003), and against the Rohingya in Myanmar (starting in 2016) met international condemnation but not concerted military action. In Syria, where a civil war has claimed hundreds of thousands of lives, U.S. air strikes in 2017 were an exception to a policy that otherwise avoided direct confrontation with the Syrian regime as it bombed and starved civilian populations.

Because the international community cannot possibly protect everyone everywhere in the world, the application of this policy is bound to be inconsistent and influenced by interests other than humanitarianism. The fact that Qaddafi was a hostile and unpredictable leader with enormous oil wealth suggests that other interests contributed to the decision to support the rebellion. No comparable interests compelled intervention in Rwanda, Sudan, or Myanmar, and Russia’s interest in preserving a friendly regime in Syria motivated it to block intervention efforts there.

Humanitarian intervention also threatens the interests that states have in exercising sovereign control over internal matters. While atrocities committed against civilians are unacceptable, states have a legitimate interest in maintaining order domestically and preserving their territorial integrity. Indeed, to some critics, the West’s recent willingness to intervene looks a good deal like another, older practice: imperialism. Just as imperial powers claimed to bring "civilization" to the lands they conquered, humanitarianism may be used to disguise self-interested efforts to undermine or take over unfriendly states.

Another concern about these operations is that military force is a blunt and costly instrument for influencing the interaction between governments and their citizens. Although the most direct way to protect civilians is to deploy troops to shield them from the government’s security forces, outsiders are usually reluctant to put their own people in harm’s way. For this reason, the Libya campaign was conducted entirely from the air, relying on bombs and cruise missiles. While this strategy was effective at preventing NATO casualties, it also limited NATO’s ability to influence events on the ground. Even if an intervention succeeds in easing a crisis, an enduring solution requires a long-term commitment by outside actors that may not be credible. When the foreigners go home, conflict may erupt again. Indeed, Libya has fallen back into civil war as different factions vie to rule that country.

Finally, humanitarian intervention raises the institutional question of who should decide when the international community can get involved. The UN is the natural venue for such a determination. Even so, for the Security Council to authorize intervention in purely domestic conflicts requires an expansive interpretation of what constitutes a "threat to international peace and security." Two members of the Security Council—China and Russia— have been loath to endorse humanitarian intervention, in part because their own human rights records are spotty. Because of the threat of their veto, the Security Council could not act against Sudan or Syria. In the case of Libya, the Security Council (with China and Russia abstaining) approved an operation to protect civilians but did not endorse the goal of ousting Qaddafi.

Supporters of humanitarian intervention have argued that NATO, as an alliance of democracies, is well qualified to act in support of human rights. But under international law, the alliance does not have the authority to undertake such an operation on its own, nor is it universally seen as an impartial force. Thus, while the international community has at times taken steps to protect people in harm’s way, it still grapples with the question of how to perform this responsibility well.