There's a wonderful exchange in Billy Wilder's fast-talking comedy of post-war Berlin, One,Two, Three, when the Coca-Cola executive, played by James Cagney, asks his German assistant: "Just what did you do in the War?" "I was in the underground," comes the reply. "You mean fighting Hitler?" asks Cagney. "No, just digging it."
Ed Miliband could say the same about Iraq. Apparently he opposed it, although few outside his circle seem to have been aware of it at the time, albeit he was close to government as an adviser to Gordon Brown. He thought, he now says, that the inspectors should have been given more time, which seems a particularly weak-kneed response to a decision to go to war.
But that, one should not forget, was very much the approach of the Brown camp, including the two Eds – Miliband and Balls – at the time. Brown's group muttered away, distancing themselves from Tony Blair's venture, but they weren't prepared to come out in the open and say it was wrong. And, when it came to it, their leader, Gordon Brown, stepped up to make sure that the party didn't vote against it by persuading Clare Short not to resign and Robin Cook to make his resignation speech before the Commons debate.
The Iraq war was, as Ed Miliband declared on Tuesday, the great defining issue of the Labour government. And the sooner the party can put clear water between it and the whole unfortunate episode the better. But it was also an issue on which the country, if not the political community, took very clear and emphatic positions, for and against. Ducking below the parapets, as so many in the Labour government did as it started, was in effect supporting it.
And that matters when it comes to trying to define what Labour's new leader means when he calls for "new generation" thinking about policy, particularly when it concerns its approach to the world at large. You can well understand David Miliband's irritation with Harriet Harman when she applauded his brother's renunciation of the Iraq invasion on Tuesday. She did vote for it at the time, as he and the rest of the cabinet and the majority of Labour MPs did.
But then David would wish Labour, as he made clear in his own speech, to hold fast to Tony Blair's vision of what he called "hard-headed internationalism". What this would seem to mean is a continuation of "humanitarian" interventionism, with Britain prancing about the world as a moral guardian instructing countries what to do. Keep up the military engagement in Afghanistan, up the ante in Burma.
The speech was hailed as a masterpiece by observers, obsessed with how he managed his references to his brother (with wit and graciousness as it happened). As a declaration of policy by the party's foreign affairs spokesman, however, it showed a man who had learned none of the lessons of Iraq, indeed a man who saw nothing wrong with it except the execution.
Not that his younger brother gave any indication of learning any lessons either. It was all very well pronouncing with a great flourish that Labour was "wrong to take Britain to war – wrong because that war was not a last resort, because we did not build sufficient alliances and because we undermined the United Nations", but then he preceded this by declaring his wholehearted approval of our military commitment to Afghanistan as "a necessary response to terrorism".
But Afghanistan isn't a "necessary response to terrorism" and, if you believe that, we'll never get out of it. The lesson of Iraq wasn't that we should have waited for more inspections or that we managed the occupation so badly. It was that going about invading other countries is the totally wrong way of approaching international issues, certainly if your intention is to help the people of the nations concerned. Afghanistan is just as much an example as Iraq.
As with expenditure cuts and university tuition fees, time is not going to allow the new Labour team to waffle on like this for very long. There are defence cuts, decisions on troop withdrawals from Afghanistan, Middle East peace discussions and actions on Iran which will very soon demand that they step up and say what they do stand for.
Don't hope too much from North Korea
One immediate challenge to David Miliband's ideal of "hard-headed internationalism" is North Korea. Most commentators, especially in the US, have greeted it with a Kremlinologist's analysis as to whether the anoinment of a new successor to Kim Jong-il in his third son bodes well for liberalisation at home and greater openness abroad. It's the wrong question.
Some repressive regimes, such as Uzbekistan, do rest on family control. But most – such as Mozambique, Burma and North Korea – are made up of groups such as the army and security services whose interests, and privileges, are served by the maintenance of a figure-headed regime. It's what keeps the system going even when the figurehead dies.
That makes predictions of future development particularly difficult to make. It also makes it especially problematic for Western outsiders to know how to influence events. Sanctions tend to reinforce regimes in power rather than undermine them. Any direct intervention tends to arouse nationalist resentment. Any hope that another force – in this case China – will do it for us runs counter to Beijing's own preference to avoid the instability of political change in its neighbours and to concentrate on commercial relations instead. Maybe the beginning of wisdom is to start with admitting what we don't know and what we can't do, before thinking what we can.
For further reading
Evidence to the Chilcot Committee ( www.iraqinquiry.org.uk/transcripts.aspx)