The lamest defence I could offer - one used by many supporters of the war as they slam into reverse gear - is that I still support the principle of i… - Johann Hari

The outbreak of cholera in Zimbabwe became a symbol of that country's collapse — but who noticed the spread of cholera across Iraq? The McCainiacs chorused that "the surge worked" — but a study by the journal Environment and Planning found the truth. Between 2003 and 2007, Iraq was ripped by a massive ethnic cleansing. The mixed Sunni-Shia areas were destroyed. By the time the surge started, there was nobody left to purge: the country was carved into ethnically homogeneous neighbourhoods. All the surge did was build vast concrete walls between the collapsing hoods, cementing the cleansing. That's success?

We have been living in an ideological bubble — one of market fundamentalism.<p>From the trauma of the Great Depression to 1973, there was a broad consensus across the democratic world that markets were absolutely essential to generate wealth, but they will also cause all sorts of problems if they are left unregulated. Economists like JM Keynes and JK Galbraith taught us that if you abolish markets, you get starvation; but if you abolish all the democratic checks and balances on markets, you get a system that eats itself. Unregulated businesses will cause unsustainable levels of pollution and inequality, and ultimately start pursuing unhinged business models that cause the whole system to collapse.

There is an emerging scientific consensus that global warming is making hurricanes more intense and more destructive. It turns out that Katrina fits into a pattern that scientists and greens have been trying to warn us about for a long time.