Syria, the case for staying out No one can here understand how the international community can let this happen. So said Marie Colvin, in an interview given from Homs, just a day before she herself was killed by a Syrian bombardment. Colvin, a gallant war reporter, put her finger on a recurring dilemma in international politics. Does the outside world have a duty to intervene to prevent the mass killing of civilians? Those who see vicious cruelty up close tend to react like Colvin. Almost all the journalists I know who covered the Bosnian war became convinced advocates of outside intervention. It is the natural human response. You see innocent people being killed, day after day. You know that there is a vast arsenal of military might, sitting back home, that could overwhelm the aggressors. It seems impossible and immoral not to advocate stopping the killing. I had a similar reaction after being appalled by a visit to East Timor, when it was under Indonesian occupation. The human rights workers and journalists who risk their lives to tell the stories of mass atrocities play a vital and honourable role. But so do the less glamorous bureaucrats and politicians, sitting safely in their offices thousands of miles away, who must try to weigh up a response. It is their job to balance the humanitarian urge to intervene, with the public duty to think through the consequences. They must ask not just "Can we stop the killing?" but "What happens next?" They must also ask: "Is it possible that, in intervening to stop one evil, we will create a greater evil in the future?" This is not a popular question. For while the advocates of intervention deal in moral absolutes, those who hang back are moral relativists - weighing one evil against another. Inevitably, they often sound shifty and heartless. But, if they make the wrong decision, they could be responsible for causing more deaths than they prevent. The current conflict in Syria poses these difficult questions in an acute form. As the killing worsens, the response of the "international community" looks feeble. It is not just the Russian and Chinese veto of a UN resolution. The Arab and western nations that are strongest in condemning Syria are also hesitating. And for good reason. The key question for any outside intervention is not only whether it can stop the killing but also whether it can decisively tip the balance in favour of a peaceful and sustainable political solution. If that does not happen, foreign intervention can simply intensify a conflict. Sometimes intervention has clearly worked. After years of hanging back, Nato did ultimately stop the Bosnian war. The more limited effort in East Timor in 1999 achieved its goals. The recent Libyan campaign almost certainly prevented a horrible massacre in Benghazi and still stands a strong chance of leaving Libya with a half-decent government. Yet, a brief glance at the news provides ample reminders of other, less successful, interventions. More than a decade after Nato troops arrived in Afghanistan - with high hopes of establishing a democracy that respected human rights - they are facing a newly inflamed insurgency. Somalia, the scene of a failed US intervention in 1993, is now the archetype of a failed state. Iraq turned into a bloodbath. Sadly, Syria looks like a country where outside intervention has a particularly strong chance of going wrong. The Assad regime has a powerful army, and more domestic and international support than Gaddafi had in Libya. If fighting escalates in Syria, the risk of a prolonged civil war is considerable. The fact that many outside powers, from Iran to Saudi Arabia to Israel, have a strong interest in who controls Syria means that there is a real chance of that war turning into a broader regional conflict. There is also no guarantee of the character of the successor regime to the Assads. The opposition forces have been endorsed not just by the US, but also by al-Qaeda, which must be a first. Remembering that western weapons once supplied the precursors to the Taliban in Afghanistan, the west should be extremely careful about who it backs and arms in Syria. Instead, through economic and diplomatic channels, the outside world should pressurise the Assads, making it clear they can never regain global acceptance. But advocates of peaceful pressure should be honest. At this stage, sanctions and condemnatory UN resolutions will probably act too slowly to stop the savagery of a government that is fighting for its life. Other apparently peaceful moves, such as setting up safe havens for refugees or humanitarian corridors for the delivery of relief, would, in fact, require the use of military force. Supplying arms to the rebels, as advocated by the Saudis, would certainly stoke the conflict. A further unpleasant truth is that, at the back of their minds, foreign policymakers must weigh the question: "How much is too much?" If this was the Holocaust or the Rwandan genocide (which claimed 800,000 lives), the imperative to intervene would rightly overwhelm fears about the consequences. The death toll in Syria is currently said to be 7,000 - and will certainly rise. That is appalling. But it does not yet justify taking on the huge risks involved in outside military intervention in Syria. I am sure if I had seen first hand the horrors that Colvin and her colleagues witnessed I would feel very differently. But sometimes distance and detachment have their place. The emotional response is not always the right response.