Philippe Couillard no doubt has his reasons for reopening the long-dormant constitutional debate in this country right now. But the Quebec premier doesn't seem to have bothered taking into account how his plans will go over in the rest of Canada.

Couillard's government is kick-starting a cross-country dialogue aimed at cementing Quebec's place within Canada and, if possible, creating the conditions in which his province can join the rest in signing the 1982 Constitution.

"We are all Quebecers, and therefore we can all say in French and in English, being Quebecer is our way of being Canadians," Couillard said in English on Thursday as he released the 152-page document (and another 40-odd pages of footnotes) setting out his government's vision for Quebec within Canada, and ways to make it happen.

It's hard to imagine anyone taking issue with such a benign platitude, especially coming from a Quebec premier with impeccable federalist credentials.

"Today in 2017, we want to increase Quebec's presence and its commitment to its federal partners," Couillard said. "Canada can be improved upon, and we want to continue doing that, especially after the unacceptable episode of the 1982 patriation of the constitution."

Distraction from other important issues

The problem is that this exact same thing has been tried before, with disastrous results.

The Meech Lake and Charlottetown accords both failed, and set the stage for the heart-wrenching 1995 referendum on sovereignty that was rejected by the narrowest of margins. That led to the Clarity Act and the Supreme Court reference case on separation.

All these events, and the responses to them, devoured time and energy, thereby preventing governments from focusing on other issues of equal importance.

Little wonder a jet-lagged Justin Trudeau wasted few words rejecting the Quebec plan on Thursday.

Prime Minister Justin Trudeau and Quebec Premier Philippe Couillard sign an infrastructure agreement in Montreal last year. (Ryan Remiorz/Canadian Press)

"You know my views on the Constitution," Trudeau told reporters in French as he arrived on Parliament Hill for the first time since returning from the NATO and G7 summits in Europe.

"We are not opening the Constitution."

The federal Liberals are not at all shy about holding public consultations on all manner of controversial topics, from legalizing pot to amending the country's anti-terrorism laws.

But the Constitution? Hold on — that's a whole different level of complexity and uncertainty.

Trudeau knows there is no emerging from that debate unscathed. And if he doesn't, he should consult Brian Mulroney (whose advice he's taking on dealing with the Trump administration) on why no good at all can come from new constitutional talks, even for the laudable goal of getting Quebec to finally sign on.

MPs muse about the proposal by Quebec Premier Philippe Couillard to reopen the Constitution. 1:44

Couillard's conditions are familiar to any Canadian old enough to remember the 1990s. Halcyon days those were not. They include: recognition of Quebec as a distinct society; a constitutional veto; and more control over immigration into the province.

Many would argue the first of those conditions has, for the most part, been met.

A decade ago, Stephen Harper fended off a trap set by the Bloc Québécois when he usurped a motion from the separatist party to have the Commons recognize Quebec "as a nation" by adding the words "inside a united Canada."

Trudeau's government appears just as willing to give Quebec a greater say over immigration.

Other grievances

The trouble is, once opened, other grievances are sure to emerge.

Saskatchewan Premier Brad Wall, for one, would almost certainly want to see the Senate abolished. Other federal and provincial politicians would surely want to take a crack at the section of the 1982 Constitution Act that enshrined equalization as a principle, to change how those payments are calculated and what provincial revenues are to be included.

Green Leader Elizabeth May would add enshrining environmental rights as something many Canadians would support.

And then there's the likelihood that any constitutional talks — or discussions or musings or negotiations — give oxygen to the Parti Québécois.

One longtime Liberal said Couillard's decision makes good on a commitment he made in the last election, and suggested Thursday's document will appeal to the big swath of Quebecers who reside somewhere between the federalists on one end and the sovereigntists on the other.

Or it can be seen as a gift to the Parti Québécois and its leader Jean-François Lisée.

"The recognition that something is really broken in Canada that lessens the power of Quebec, the health of Quebec, the ability of Quebec to make its own decisions, is welcome," Lisée said Thursday.

Hope may emerge for a renewed dialogue that is, according to the document, "designed to allow Quebec's full adhesion to the Canadian constitutional order."

But with hope comes the prospect of more divisions, more acrimony, more time and effort spent not dealing with the other important issues of the day such as climate change, rising house prices and trade disputes that affect Canadians and Quebecers in equal measure.

When you consider it all, Pandora herself might resist opening this box as Canada prepares to celebrate its 150th birthday.