A dilemma is by its very nature a choice between evils, and that is what now faces other countries over the use of poison gas in Syria. All the options may be "on the table," but none of them are good.
Nobody denies that poison gas was used in rebel-held parts of Damascus on 21 August, not even the Syrian government. Medecins Sans Frontieres says 3,600 patients with symptoms of poisoning were treated at three hospitals it supports in Damascus after the attack, and that at least 355 of them died. The real total may be as high as 1,000 dead. That's a whole week's normal death toll in the Syrian civil war in just one day.
After that, however, we run out of facts. The rebels claim that the Baathist regime was responsible, while the Syrian government says that the rebels did it themselves in the hope of triggering foreign military intervention. Sending United Nations inspectors will not settle that argument: if nerve gas was actually used, it must have come from government stocks, but that doesn't mean that the regime did it.
Everybody knows that the Syrian military have stocks of poison gas, but what's happening in Syria is a civil war. The rebels have not overrun any of the known storage sites for Syrian chemical weapons, but they could have secret supporters inside those sites that smuggled some out to them.
If you apply the old test of "who benefits?" the rebels, who are currently losing ground, have a strong incentive to get the Assad regime blamed for using illegal weapons. If that gets the United States and other Western powers to impose a no-fly zone, or bomb the regime's military bases, it helps the rebel cause. So maybe they acted to provide the necessary "evidence:" some of them are certainly ruthless enough.
It's easier to imagine the regime using chemical weapons: it's just as ruthless, and it actually owns them. But it is manifestly not to its advantage to do so. President Bashar al-Assad's troops are winning the war without them, and the last thing he needs is foreign military intervention. Using chemical weapons could lead to just such an outcome, and it would be exceptionally stupid for the regime to do so.
On the other hand, armies and regimes have done exceptionally stupid things in the past, particularly when they are isolated and under great pressure. The emerging consensus among Western governments, at any rate, is that Assad was responsible. So what to do about it?
France has already called for the use of force, and the United States and Britain seem to be teetering on the brink: after a 40-minute phone call last Saturday President Barack Obama and Prime Minister David Cameron agreed that "a significant use of chemical weapons would merit a serious response." But that is about the least they could say, in the circumstances.
Earlier in the week, Obama warned publicly that people who "call for immediate action, jumping into stuff that does not turn out well, gets us mired in very difficult situations, (and) can...actually breed more resentment in the region." If you liked America's wars in Afghanistan and Iraq, he is saying, you'll just love the one in Syria — and he knows the American public is not up for it.
U.S. military intervention is unlikely to lead to the outcome American foreign policy really desires: the preservation of Syria's existing secular state, with a change of leadership at the top. If Assad is overthrown, he'll probably pull the whole edifice down with him. If the rebels win, it's almost certainly the Islamist radicals who will take over. So if a military intervention is practically bound to end in tears, then why not just skip it?
Because chemical weapons are classed as "weapons of mass destruction," and there is an international treaty banning their use. If you let Assad get away with this, goes the argument, he will have breached an important international taboo on the use of WMD. Well, not really.
Biological weapons ("germ warfare") are truly horrifying weapons of mass destruction, banned by treaty, and nobody has ever used them. Nuclear weapons can kill by the billions; they have never been banned, but they haven't been used in war for 68 years now. Poison gas, however, is not really a weapon of mass destruction at all.
When gas was used in the First World War, it was always about capturing the next line of trenches. After that war it was banned, but it has been used a few times since: Italy used gas in Ethiopia in 1935; Japan used it against China in 1938; Yemen used it against rebels in the 1960s; and Iraq used it against Iran and Kurdish rebels in the 1980s. In no case did the casualties reach "mass destruction" levels.
Napalm, fuel-air explosives and cluster bombs are just as nasty as poison gas, and perfectly legal. The historic ban on poison gas is a valuable deterrent, but it has survived some previous breaches, and preventing this one is not worth a war. Especially if it is, from the point of view of the potential interveners, an unwinnable war.
Gwynne Dyer is an independent journalist whose articles are published in 45 countries.