At times the Prime Minister appears almost alone as he defends his attempt to stay close to the United States while being a good European. The legacy, it is said, is one of undiluted failure, symbolised by Iraq, the “worst mistake since Suez” and the burden of a man who promised so much (in both senses of the term) but ultimately, tragically, sacrificed his reputation in backing a US president whose idea of diplomacy is less Henry Kissinger than Clint Eastwood.

That is the approved script. But it is not the true picture of the past decade. Tony Blair is not responsible for everything that has happened during his time in Downing Street, any more than Queen Victoria created an empire. Yet Britain’s ranking in the international pecking order has to be partly due to the deeds of the Prime Minister of the day. And the legacy of the period since 1997 is enhanced British power.

Power in international politics comes, broadly, in three forms: economic weight, political authority and cultural influence. The transformation in Britain’s economic status is staggering. When I was a child the sense of inevitable national decline was overwhelming. It was a state of abject catastrophe that was reversed by Margaret Thatcher as Prime Minister. Her rather unlikely political stepson has cemented that recovery.

Over the past decade Britain has enjoyed the highest rate of economic growth of any G8 country other than America. It has moved from the sixth largest economy in the world, where it slipped during the nadir of John Major’s tenure, to the fourth greatest. Our lead over France and Italy has become entrenched. The UK has shifted from a manufacturing base that had little future to a service sector focused on high-value products. New York City is at risk of losing its status as a financial centre to London for the first time since the 1920s.Economic power is the basis of foreign policy power. It has been strengthened.

What of political power? Think of Mr Blair’s two pillars. The US-UK alliance had some dire moments during the Major years. That Prime Minister had no impact on the EU, either. The sum of his achievements there was vetoing a federalist prime minister of Belgium for the post of President of the European Commission in order to insert a federalist prime minister of Luxembourg into that portfolio instead. Jacques Santer (remember him?) was later driven out of the Commission for his sheer incompetence.

Whatever one might think of the decisions that Mr Blair has taken, the notion that the UK-US “special relationship” is an anachronism is today incredible. From Kosovo to Afghanistan to, yes, Iraq, its presence has been profound. Most prominent Democrats (certainly Hillary Clinton) believe that the Prime Minister was right to do what he did in tandem with the Bush White House. Their principal objection to the Blair role in Iraq is that he was so irritatingly eloquent in echoing a Republican president’s message.

Europe, as well, has changed beyond recognition. The aim of widening the EU was shared by the Major and the Blair governments. It was absurd that the door to the East was not opened much earlier. Now, the EU has almost doubled in members from 15 to 27 states. There is plenty of evidence that Europe will be a more comfortable place for Britain politically. When Mr Blair vetoed a federalist Belgian prime minister for the presidency of the EU Commission in 2004 he was, unlike his predecessor, not alone and the replacement was a Portuguese free-marketeer. That, in a nutshell, has been the distinction between the Major and Blair eras. Mr Blair will leave his successor a far, far stronger hand than he was bequeathed.

Finally, there is cultural power. Since Mr Blair (unlike Al Gore) has never claimed that he invented the internet, his direct part in pressing forward Britain’s cultural standing is limited. Yet in the past decade the English language has become ever more important. That can be seen in the demand for places at British universities from overseas and in the boom in higher education establishments opening up satellite sites abroad. The concept of degree certificates as postmodern gunboats might seem surreal, but this is, to use a voguish phrase, “soft power” in action. It has been repeated in fields as diverse as fiction, food and football. Britain has become a brand.

All of which leads to what might appear an outlandish claim. It is that the real foreign policy legacy of the Blair years is that Britain has become the second most powerful country in the world.

To be sure, we stand a long way behind the United States, and it may not be many years before China pushes us into bronze medal position. Yet, who else could plausibly be given the silver? Germany and Japan might have larger economies than the UK but they have been in the economic doldrums for most of the past ten years and remain incapable of deploying troops overseas with any confidence.

France and Italy, too, have been in economic, political and cultural decline. Russia under Vladimir Putin cannot be dismissed, as the Soviet Union was, as “Upper Volta with nuclear missiles” — but “Nigeria with nuclear missiles” is not far wrong.

The underlying reason why Britain’s military has been overstretched since 1997 is that our position in international affairs has expanded. Mr Blair’s real failure in foreign policy has not, therefore, occurred in Baghdad or Basra. It is that he has not convinced his countrymen of the extent of Britain’s revival.