It is time for real compromise in Libya. The principal reason to support the intervention in the first place was to protect the people of Libya. Decisive action aligned the west with popular movements sweeping the Middle East and north Africa - a goal justified by both ideals and interests. For the same reasons, stopping the fighting now is more important than an opposition victory on the current terms advocated by the National Transitional Council in Benghazi. Some conditions remain non-negotiable. Muammer Gaddafi must step down. If he remains inside Libya, it must be in a place and on terms that prevent him from maintaining a personal power base. The fighting must stop and both sides must pull out of population centres. But everything else should be on the table. Remember how the intervention began. The only ground on which the Arab world and then the United Nations could agree on the use of force was the protection of Libyan civilians. Security Council resolution 1973, which authorised the no-fly zone and other measures, listed a long set of humanitarian concerns and justifications, beginning with the responsibility of the Libyan authorities to protect the Libyan population, and noting the perpetration of gross and systematic human rights violations and possible crimes against humanity. On April 14 Nato and its partners announced that they would continue a high operational tempo against legitimate targets (ie, intensive bombing) until Col Gaddafi ended attacks and threats of attacks against civilians and civilian-populated areas, verifiably withdrew all his forces to bases, and permitted humanitarian access to all Libyans who need help. Those are genuine humanitarian conditions, but de facto they would require Col Gaddafi to give up all the military gains he has made against opposition forces by pulling out of all the cities that are currently contested. He has no incentive to give up the fruits of his military victories except in return for an acceptable political agreement with the opposition. Here is where the views of leading coalition members come into play. The US, Britain and France appear to have political red lines of their own, most notably the non-participation of any Gaddafi family members in some kind of transitional governing arrangement. Since Col Gaddafi himself has refused any suggestion that does not include the face-saving formula of allowing him to transition at least some power to one of his sons, real progress is stymied until Col Gaddafi is killed either by a bomb or one of his own associates. Yet none of his family members have any incentive to advocate compromise, as his fate and theirs are tied. I fully understand why the idea of any member of the Gaddafi family continuing to hold power of any kind is so repugnant. I in no way accept a moral equivalence between the two sides; Col Gaddafis abuse of his own people extends back nearly a half century. I was an early and vocal supporter of the UN intervention in Libya precisely because I foresaw that Col Gaddafis ruthlessness and disregard for the lives and prospects of his citizens imperilled a city of 700,000 people. I also share the genuine commitment of many in the NTC to create a liberal democratic Libya that protects and empowers all Libyans. Yet it is time to rethink, because the longer the fighting continues, the longer it is likely to continue. This is counter-intuitive; both sides assume that each is wearing the other down and thus victory is just a matter of weeks or months. But in a conflict like this one, where for various reasons neither side has the ability to deliver a decisive blow, the fighting itself creates a cycle of radicalisation and entrenchment that makes it progressively harder rather than easier to reach a settlement. At the outset, I and many others saw the conflict not as a civil war but as an uprising of the Libyan people against their government. I continue to think that widespread opposition to Gaddafi exists in Tripoli and across Western Libya. But opposition to Gaddafi has not translated into mass uprising or manifest support for the Benghazi forces, in no small part because the more family members lose loved ones, suffer prolonged privation and life disruption, and are victims of the kinds of human rights abuses that reporters and non-government organisation observers are beginning to document on the part of opposition forces, the more reason they have to believe Col Gaddafis propaganda and conclude that the devil they know is better than the devil they dont. The more sacrifices individual fighters make for their cause the more they hate and harden their positions, on the grounds that only a complete victory can justify the mounting costs of the struggle. The longer the fighting continues, the more opposition members will have blood on their hands as well. Moreover, the destruction of ongoing warfare undermines the economic and social preconditions for any meaningful political order in Libya over the coming years. Meanwhile, the human costs to the Libyan people that Nato seeks to protect mount daily. In battle zones, widespread death and rape, with the attendant destruction of families and the all-too-human desire for revenge. The destruction of vital infrastructure necessary for economic activity, from oil production to ordinary small business. The flooding of the country as a whole with arms, which will spur further conflicts and raise the overall levels of violence in communities across the country. The continued shortages of food, medicine, power and other basic necessities of life, the disruption of education, business, travel, and interaction with the outside world. The deepening of tribal divisions and ancient enmities across the country. All this will make it much harder to rebuild a Libya with a government that actually serves rather than oppresses its people: the ultimate goal not just in Tripoli, but across north Africa and the Middle East. We have seen such a political tragedy unfold many times before, in Iraq, Afghanistan, Somalia and the Democratic Republic of Congo. The relative success stories, such as East Timor and Kosovo, are ones where the fighting ended quickly once the basic objective had been achieved. It is time to explore all possible avenues to add Libya to that list. Financial Times