In 2005 the United Nations General Assembly unanimously embraced the principal that each state has a “responsibility to protect” its citizens from crimes against humanity. This language was included in a recent UN Security Council resolution – an historic first. When a state is unable to live up to this responsibility, and especially when that state is itself perpetrating such crimes, it falls upon the international community, acting through the UN Security Council to fulfill it.

A no-fly zone that grounded Qaddafi’s planes would prevent direct bombing or strafing of civilians and block further transport of mercenaries and weapons into the country. Helicopter gunships would be harder to track and ground, but targeting those that are found would act as a deterrent to their use against civilians. A no-fly zone would also act as an incentive for those flying with Qaddafi to defect, and would send a strong message to other challenged leaders about the consequences of using force against their own civilians.

It is important to point out that implementation of a no-fly zone is not a question of feasibility, but rather one of assumed risk. As Secretary of Defense Robert Gates has stated it would be complex and risky, but “if it’s ordered, we can do it.” Gates rightly points out that a no-fly zone would require attacks on Libya’s air defense system, a military action opening up the risks of planes being shot down, and collateral damage.

But the risks should not be overstated. According to military experts, the Libyan air defense system is antiquated and Qaddafi has a limited number of air bases, some already in opposition hands. Also, as Senator John KerryJohn Forbes KerryJohn Kerry’s memoir title revealed GOP senator: Democratic opposition to Pompeo 'driven 100 percent by politics' North Korea is moved by Pompeo diplomacy, but Dems dig in deeper MORE has pointed out, airports and runways could be cratered, grounding Qaddafi’s fighter jets and thus creating an impact even before all air defense systems are taken out.

Other critics warn of a slippery slope and mission creep. This need not be the case. A no-fly zone fits into what the military calls Flexible Deterrent Options, intended to be used in concert with diplomatic, economic and political options short of actual combat. Setting out clear rules of engagement with the primary objective of protecting civilians can avoid any inevitability of a no-fly zone leading to a prolonged air and ground war.

It is also important to recognize that the United States should not, and would not, be alone in recognizing a no-fly zone. While countries like China, Russia and Turkey have shown reservations about a no-fly zone, the idea has been discussed openly by European leaders and endorsed by the Organization of the Islamic Conference and by the Arab League. The Gulf Cooperation Council has demanded “that the UN Security Council take all necessary measures to protect civilians, including enforcing a no-fly zone over Libya." Perhaps most importantly Libyans representing the National Transitional Council have called for a no-fly zone.

The United States should urge its international partners to call for the Security Council to immediately authorize preparation of a no-fly zone, possibly led by NATO in cooperation with the African Union and/or Arab League.

A no-fly zone is not a silver bullet and alone would not be sufficient. It would neither ensure the end of Qaddafi’s regime nor prevent the possible targeting of civilians by ground forces. Other steps could include deploying signal-jamming aircraft to disrupt government communications, anti-jamming aircraft to prevent Qaddafi from jamming opposition cell phones and internet, and setting up a UN-authorized escrow account that could cut off oil revenues to the regime and hold it on behalf of the next government in Libya.

A no-fly zone should be implemented with full awareness of the risks, complexities and limitations and with as much international support as possible. But the actions we have seen from Qaddafi already and the calls from the people he has attacked attest to the high costs of not acting. We have an international responsibility to do more to protect Libyan civilians and ensure that more innocent lives are not lost. In the end, a no-fly zone is not only an international obligation and logistically doable, it is also the right thing to do.

Daniel P. Sullivan is senior policy analyst for the recently merged Genocide Intervention Network / Save Darfur Coalition.