As Britain’s Prime Minister, Tony Blair achieved many goals: Under his watch, six million Britons climbed out of poverty, crime in the U.K. plummeted by 35 per cent and the economy soared, almost without break, for ten years. (All these numbers according the Globe’s Doug Saunders.)

As a diplomat, too, Blair had many victories. His efforts to seal peace in Northern Ireland were so unerring that he may be the first British leader in a thousand years remembered as a true friend of the Irish. And Britain’s relationships with both the United States and the European Union are better now than they were ten years ago.

But for all Blair’s good moves, it is for a wrong one that he will be most remembered. As the BBC’s Diplomatic correspondent James Robbins put it: “Iraq...Iraq...Iraq...Tony Blair's fateful decision to invade will overshadow everything else when history judges his conduct of foreign policy.”

Or, to put it in the words of the mostly sympathetic Timothy Garton Ash, “Blair keeps insisting that history will give the verdict on Iraq, but we can already say this with confidence: Iraq is a disaster.”

As leader of a nation you are called upon to make a small few enormous decisions. And if you make the wrong call on just one, as Blair did, it can cost thousands, if not millions of lives, divide your country and forever stain your legacy.

It is also worth noting when Blair was making his fateful choice, our current Prime Minister, the man now having to make similar choices about our participation in Afghanistan, was fully on his side. As the Walrus’s Jeremy Keehn wrote in The Tyee last year, Stephen Harper repeatedly and vehemently excoriated the then governing Liberals’ decision not to participate in the U.S. led invasion.

And while Harper later distanced himself from those comments, the record will show that when Jean Chretien was going one way and Tony Blair the other on arguably the single most important decision of either of their tenures, Stephen Harper had this to say:

A coalition of countries under the leadership of the U.K. and the U.S. is leading a military intervention to disarm Saddam Hussein. Yet Prime Minister Jean Chretien has left Canada outside this multilateral coalition of nations. This is a serious mistake.