When you reflect on the war in Iraq – on the false assumptions, on all the errors of execution, on the price already paid – it is hard to believe that wishful thinking could still be the prevailing mode of analysis. Yet it is, and on both sides. George W. Bush thinks that the US is winning, and will prevail if the country “stays the course”. The president’s critics are not much less deluded. Their solution is rapid withdrawal of American forces. Just quit, and the US can start to put the whole mess behind it.

If only that were true. Awful as it is to contemplate, things can get much worse in Iraq and in no plausible scenario are they likely any time soon to get better. Success, meaning victory or clean disengagement, is not an option. The question is how to control the damage. The US needs consensus around a strategy not to “win” and not to “bring America home” – the first is impossible, the second very risky – but to dig in for a protracted, limited and hence (with luck) feasible effort to contain the harm. Perhaps by default that is where policy will end up, under either this president or the next. Meanwhile, though, an honest discussion of the issue in those gloomy but realistic terms has barely even begun.