''Aussies know how to fight, and I like having them in a foxhole if we're in trouble.'' So said US President Barack Obama as he refused to rule out a military response to this week’s extremist takeover of key Iraqi cities. PM Tony Abbott also “won’t rule out” sending Australian troops into the quagmire. As Guy Rundle wrote in Crikey yesterday, it’s impossible to overestimate the significance of the advance of militant group ISIS across Iraq. But military intervention? Didn’t we try and fail at that before? Yes, a coalition of Western military forces might turn back the tide of extremists in Iraq -- or it might not. The latter is much more likely if past experience is a guide: as Bernard Keane writes today, the Iraq War was a multitrillion-dollar exercise in making Western citizens “less safe from terrorism”. Australia’s involvement was also done without the support of our Parliament and on false pretenses. Any future involvement in military action in that country must be properly debated, and advocates must explain exactly what we're seeking to achieve and how we know we'll achieve it. And before the US seriously contemplates any involvement, it should ask itself the one hard question the Bush administration and its cheerleaders in London and Canberra never asked: what exactly is the path out of such conflict? Because starting another war to prop up the Iraqi government could become immensely problematic if such a government can never govern Iraq. Abbott’s sabre rattling in the US might work to impress the neocons, but this is one foxhole Australia should not be going down.