Illustration: John Spooner The indulgence, too, of Iraq. This is not to deny the rude shock last year when IS screamed onto the world stage by taking Mosul, Iraq's second-largest city. But Iraq as we knew it no longer exists. The north, which IS controls, is a different country now. The Sunnis living there have little desire to be part of what they consider to be a repressively Shiite state governed from Baghdad, and the southern Shiites seem equally content to cut the Sunnis loose. We don't talk much about Baghdad any more, partly because life is more normal and mundane there than it has been in years. Investment is up, and suicide bombing is down. Television airs sitcoms ridiculing IS and pop songs do the same. As Nicolas Pelham recently wrote in The New York Review of Books, southern Iraqis talk about IS in the past tense. Even if the Iraqi state could launch some military assault on the north, you get the distinct impression it couldn't be bothered. Then there's the indulgence of Turkey, which was happy to let Sunni terrorists pour over its border into Syria for years when IS was just a lad. Here, Turkey had two interests. First, to facilitate any opposition to Assad that it could. And second, to ensure its Kurdish population couldn't use the chaos to establish their own proto-state. Turkey is now a mirror image of Russia: a proud, once-imperial nation led by a macho aggressor determined to entrench its interests, subdue its separatists and act on behalf of its ethnic brethren. So, as Russia nicked Crimea off Ukraine in the name of protecting the Russian-speaking population, so too is Turkey enraged at Russia's air strikes on Syria which drop bombs on ethnic Turkmen. Russia, meanwhile, cheerfully bombs anyone opposed to Assad as a way to preserve him and maintain its own regional power. So for Putin, IS is simply convenient rhetorical cover that allows him to bomb whoever stands in Assad's way.

Illustration: Simon Letch No one likes IS, but everyone ultimately has greater, conflicting concerns. Partly that's because most nations recognise IS has no air force, no history of military victories against capable enemies and controls a largely empty swath of land, which it has recently commenced losing. Western nations might be keen to see that process complete itself, but the truth is they have little appetite for making it happen. Western populations have tired of war – a fact reflected in an Essential poll this week revealing that even so soon after Paris, fewer than a third of Australians want to see us step up our military involvement. But even more seriously, there's the stench of futility here. That same poll has only 17 per cent of us believing it would even make us safer if we did, and 45 per cent believing the opposite. A Turkish army truck loaded with a self-propelled gun heads to the Syrian border near Yayladagi on Wednesday. Credit:AP That's why it's hard to see us rushing into a full-scale war. Sure, we could crush IS, but what then? Would we end up delivering land to the Kurds, and enraging Turkey? Or back to Assad, which would bolster Russia's power and entrench a dictator whose own body count simply dwarfs IS's? And what of the far likelier result that the land ends up contested by scores of warring groups engaged in an encore performance of the carnage in Iraq that gave birth to IS in the first place?

In the visceral urge to smash things after Paris, you can overlook the fact that whenever we've tried to use our armies to smash terrorism we've generally scattered it all over the world. Remember when US president George W. Bush said we were fighting terrorists in Baghdad so we wouldn't have to fight them in Boston? And remember how, not so long ago, bombs went off in Boston? The idea that we can gather terrorism in one place and then destroy it is now surely one of the most demonstrably wrongheaded of our age. Islamic State exists because it gets lost amid the much bigger fights going on around it – you know, between armies that actually have planes to shoot down. It takes a special kind of ideologically induced amnesia to ignore all this. It's an amnesia that takes centre stage in the American Republican party and the lunatic fringe of our own Coalition. But if Malcolm Turnbull is to be believed, this amnesia is not taking hold of Western leaders more generally. That's because they understand IS isn't a player. It's the Middle East's illegitimate child: a byproduct of the power vacuums of a broken region. It exists because it gets lost amid the much bigger fights going on around it – you know, between armies that actually have planes to shoot down. And you can do what you will to IS. Until those bigger fights are somehow resolved, there will always be a byproduct. Waleed Aly is a Fairfax Media columnist and winner of the 2014 Walkley award for best columnist. He also lectures in politics at Monash University.