Just because Tony Blair is going does not mean that he can, or should, be ignored. But even when he has interesting things to say, he is being treated as part of the past and of no relevance to the future. That is the price Mr Blair is paying for his long goodbye, his endless departure and extensive farewell tours and events. Even the substance of his visits to Libya and South Africa has tended to be lost.

But Mr Blair’s reflections on his decade in office deserve serious attention. The three-page essay he has written for The Economist, entitled “What I’ve learned”, is more than just a lengthy apologia. It is a timely corrective to the sprawling and self-indulgent Labour debate about post-Blairism.

Mr Blair remains an unapologetic interventionist around the key themes of “be a player not a spectator”, “transatlantic cooperation is still vital” and “be very clear about global terrorism”. Of course, everything Mr Blair says is bound to be seen through the prism of the bloodshed and horrors of Iraq since 2003. He cannot, and does not want to, escape his record.

The most revealing phrase in Mr Blair’s article is: “Get real.” The implicit message is that “soft power” – diplomacy, cultural influence, backing reconciliation and aid for economic reconstruction (what Gordon Brown likes to discuss) – is all very well. But you cannot avoid “hard power”: the willingness to confront terrorism, if necessary with military force.

The danger in the reaction to Iraq on the Left is a retreat in evasion and wishful thinking, as displayed by some of the candidates for the Labour deputy leadership. Their search for a comfortable alternative is a delusion. That is what Mr Blair has in mind when he writes about “a drifting away, occasionally a resurgent isolationism that crosses Right and Left”. He attacks both Euroscepticism and the desire for “an independent foreign policy” from America, a ritual chant in many Left-wing articles and speeches. As Mr Blair says: “Quite where Britain is supposed to get its alliances from bewilders me. There is talk of Britain having a new strategic relationship with China and India, bypassing our traditional European and American links. Get real.” Europe and America should stick together. But this means a strong EU, with closer cooperation and effective institutions.

The key test for Mr Brown will be the balance between a different tone – less self-justificatory and less personally close to President George W. Bush – and any policy changes. Merely by not being Mr Blair, Mr Brown will have greater flexibility, not least in admitting the errors that have been made. There are obviously questions about the timing of the withdrawal of British troops, but the direction is clear.

Mr Brown will want to appear postBlair while remaining hardheaded about the strategic choices. He knows that gesture politics dictated by widespread dislike of the Bush Administration will achieve little. And, anyway, there will be a new US President in January 2009.

The Brown inner circle may be reluctant to take much notice of Mr Blair as a messenger when they have their own plans. But they should take note of his message.

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