It's all been very entertaining, in its way, and I should probably feel sadder at the thought that we have just seen the last of them. After the vaudeville routine the premiers put on at last week's news conference in Moscow, grabbing for the microphone like a gang of drunken exchange students on karaoke night, the chances that they will ever again be allowed to tag along on the Prime Minister's travels must be rated next to zero.

It isn't just the appalling personal humiliation inflicted on the Prime Minister, smiling weakly as a giggling Ralph Klein pulled the premiers' letter from his pocket and read it out in front of the world media. It isn't even the presumptuousness of these jumped-up little pothole-fixers, sonorously declaring that "the government of Canada's position" on the Kyoto climate treaty "is not consistent with the position of all the premiers," as if they were some sort of council of elders to whom the federal government must report.

No, ask not why the premiers behave so disgracefully on these trips -- remember the contretemps over the minivans, on that first trip to China, when the premiers threw a hissy fit at being forced to ride behind the Prime Minister's limousine in the official motorcade? Ask, instead, why they are even there.

If the premiers have deluded themselves into believing they have a hand in negotiating international treaties, foreign affairs having been added to the long list of other federal powers into which they have sunk their fangs, they can only be encouraged in this psychopathy by their inclusion in federal trade missions. The heads of government of other federations, after all, do not feel compelled to take the kids, as it were, when they travel. When the President of the United States goes abroad, he does not pack all 50 governors on Air Force One with him. Neither does the Prime Minister of Australia, nor the Chancellor of Germany, nor any other federal leader you can think of.

It goes without saying, in these other federations, that international trade and foreign affairs are exclusively federal jurisdictions. They are a good part of what a federal government is for: to speak with one voice on the world stage, which being one will sound the louder. Indeed, a federal government that can do such things is the only reason to form a federation.

Only in Canada do we pack up all our internal divisions and petty jealousies and parade them before the world. Only in Canada is the federal government so infirm of purpose that it cannot break free of its provincial minders, even overseas. Even here, as I mentioned, the practice is quite new, the idea first emerging at a gathering of "First Ministers" in 1993. (First Ministers' meetings are themselves a relative novelty: Diefenbaker held the first.)

Possibly some well-meaning boffin in the Privy Council Office thought it would purchase the feds some goodwill, in those nervous times between the collapse of Meech Lake and Referendum II. But the lesson of all constitutional history in Canada is that provinces do not ever accept an enlargement of their role as an end point, or even a bargaining chip, but rather as the appetizer for the grander feast of federal powers to come.

There's no evidence that the premiers' presence adds much to the "success" of these missions, such as it is: Most of the deals have long since been negotiated, and would have been with or without the Moonie-style mass signing ceremonies the politicians find so enchanting. On their famous "lost in Latin America" tour in 1998, the premiers cooled their heels for days waiting for the Prime Minister, who was detained by the ice storm. Mr.

Klein was heard pleading for Mr. ChrŽtien to come as soon as possible: Mexico was all right, but "none of us really knows about Brazil." We have already seen what provincial infighting has done to our bargaining position in the softwood lumber mess. Far from an example of how "federalism can work," the intrusion of the provinces into these matters, with all their many and shifting positions -- Bernard Landry, odd man out again, pronounced himself in favour of something called the "Tokyo Accord" -- only serves to highlight how dysfunctional our federation truly is.

Or perhaps I asked the wrong question off the top. If, as their rhetoric and their presence suggests, the premiers can claim to represent Canada abroad, why bring the PM?