The war in SyriaDeath from the skiesThe growing horror of the Syrian civil war has put military intervention back on the agendaSep 15th 2012 | IDLEB PROVINCE AND LONDON| from the print editionTHE rebel fighters, lolling sleepily in a former police station, are suddenly interrupted by a rocket that crashes into the roof over an unoccupied room. Although the Syrian regime has ceded direct control over this and much of the rest of Idleb, a rural province in the north-west, shelling and other attacks from a distance are a frequent annoyanceand worse. As night falls, behind closed doors, a woman sits guessing which village the distant thud of falling shells is coming from tonight. Her children, meanwhile, are busy describing in detail how the mother of a friend had her limbs torn off by a rocket.For all their risks, such villages look like positive havens to the Syrians fleeing Aleppo, the countrys second city and now its primary battleground. The government and the rebels have been trading turf back and forth along the front line since the grinding battle started in July. One day the rebels take an army barracks; the next the regime claims to have grabbed it back. Meanwhile, in the suburbs around Damascus, corpses of young men with their hands tied behind their backs are piling up. Shelling continues from Deir ez-Zor in the east to the southern plains of Deraa, as do air raids. Fighting rages in every province.In this sectionDeath from the skiesMeddling at their perilEntropy increasingReprintsRelated topicsInternational lawLawCrime and lawIsraelTurkeyAs the civilian death toll rises, the question of whether other countries should intervene with armed force is becoming acute. Opposition groups estimate that August was by far the bloodiest month since the uprising began in March last year, accounting for a fifth of the estimated 25,000 to have died so far (see chart). Michael Clarke, the director of the Royal United Services Institute, a think-tank in London, believes that the preference Europe and America have shown for staying out of the conflict, at least in terms of military action, is being worn down by both the scale of the suffering and the threat it now poses to the stability of fragile neighbouring countries. “We are not moving towards intervention,” he says. “But intervention is certainly moving towards us.”There are several reasons for the escalation of brutality over the summer. Opposition fighters in the Free Syrian Army were over-confident in attempting to hold parts of Damascus and Aleppo before they had the means of doing so; counter-attacks concentrated the violence in places where there were lots of civilians to get hurt. And the regime of Bashar Assad appears to have discarded any form of restraint. That is partly because of its own increasing desperation, but also because in the past it was not sure how far the international community would let it go. Now it has crossed more or less all the “red lines” that Western politicians had hoped it would respect. The use of chemical weapons seems the only thing that would be certain to trigger a military response from outside.The clearest indication that Syria no longer cares about calibrating its use of violence has been the growing use of air power, first with helicopter gunships, then with fighter jets. The air campaign allows the regime to terrorise and punish areas where it has lost control and to conserve its ground forces, especially its tanks, which have become more vulnerable as the rebels have grown in experience.Aerial attacks also have the advantage of depending on a part of the armed forces which is almost entirely controlled by Alawites, the sect to which the Assad family adheres. Mr Assads father, Hafez, ran the air force before he launched the coup that brought him to power in 1970. It is reasonably well equipped, with perhaps 325 aeroplanes that can be used for ground attack and 33 helicopter gunships, and its personnel are thought less prone to defection than army officers have proved.The legal questionsIf nothing happens to limit Mr Assads deployment of air power, the rebels will struggle to make further gains and may themselves become more savage in their frustration. The civilian death toll will continue to mount. The flow of refugees into neighbouring countries4,000 a day are trying to cross into Turkeywill grow.But what limits on the regimes violence might the West and the uprisings Sunni Arab supporters, such as Saudi Arabia, the United Arab Emirates and Qatar, imposeand to what purpose? The options include providing the rebels with more anti-aircraft weapons; establishing a humanitarian corridor from north of Aleppo to the border with Turkey under the protection of outside forces, a call made by Frances president, Franois Hollande, and Turkeys foreign minister, Ahmet Davutoglu, in the first week of September; enforcing a no-fly zone over the entire country; and actively seeking to end the regime. Each of