It all started when Premier Lucien Bouchard, in a moment of passion he must now regret, dispatched an angry letter to Frank McKenna in protest at yet another letter, in which the then premier of New Brunswick had expressed his support for the partitionist movement in Quebec. That apparently marked the start of correspondence season, for ever since Dion has taken to bombarding Quebec City with closely-argued prose every time a PQ cabinet minister peeks his head over the ramparts. Dazed by this ceaseless barrage, the PQ has been slower and slower to answer, to the cheers of federalists everywhere.

Yet in the latest edition of this bataille des feuilles, I find myself more in sympathy with the position of Dion's interlocutor, Quebec Inter- governmental Affairs minister Jacques Brassard. Not that there was anything new or persuasive in Brassard 's November 12 declaration to the Quebec legislature, which was little more than a formal restatement of established PQ dogma on partition: viz. that Canada is divisible, but Quebec is not. "The territorial integrity of Quebec is guaranteed," Brassard solemnly intoned, "before, during and after achieving sovereignty." Before, certainly: under the constitution of Canada, the boundaries of a province may not be changed without its consent. After, without a doubt: international law is just as clear in defense of the territorial integrity of sovereign states.

But during?

The PQ has always tended to gloss over a painful discontinuity that must inevitably interrupt any attempt to pass through the looking glass into independence. To get from one side to the other, the PQ must declare independence unilaterally, in violation both of the constitution and of domestic law -- in which case it can hardly claim the protection of either.

The only alternative is to seek Canada's consent for a lawful secession, in which case the question of borders would be very much on the table.

The same international law, as Dion points out in his letter, that would protect a sovereign Quebec from an involuntary partition also protects Canada from the same fate. The only way that both these principles can apply simultaneously is if Quebec achieves independence with Canada's consent.

Still, there is something refreshing in Brassard's unapologetic defence of the right of a state to assert its territorial integrity, even if this means denying the right to secede to minorities within its borders. The principle of indivisibility is correct: where he errs is not in applying it to Quebec, but in denying it to Canada.

Contrast this with Dion's position. Though he is brave enough to insist that a seceding Quebec could not take its present borders for granted, the minister cannot bring himself to offer any stronger defence of Canada's own territorial integrity. While noting that "many very respectable democracies have explicitly or implicitly prohibited secessions in their constitutions," Dion insists that Canada would not stand in Quebec's way. "We believe that our country would no longer be the same if it were not based on the voluntary adhesions of all its components." So in place of the Brassard doctrine -- Canada is divisible, but Quebec is not -- we have the Dion postulate: everybody is divisible, Canada as much as Quebec. To do as the other "respectable democracies," he says, and prohibit secession outright, would require Canada "to keep Quebecers in Canada against their will." Yet that is precisely what he would do, in certain circumstances: in the event of a UDI, Canada would withhold its consent.

What is more, the present government has already laid down such conditions for secession, including the possible partition of Quebec, as to make a UDI the only option available to a secessionist regime.

So: Quebec can go, but only if we say so. Or: Quebec can't go, unless it asks us nicely. However it is expressed, Dion's position is just as internally contradictory as the PQ's. Canada, it seems, is both divisible and indivisible at the same time.

This is no way for a self-respecting nation-state to behave. If Quebec has enough sense of its own legitimacy to assert that its borders are inviolable, so should Canada. Or to rework an old phrase, "If Quebec is indivisible, so is Canada."