Fine Gael playing of Green card in this high stakes game is genuinely alarming
If Leo Varadkar was to be visited by the ghosts of Christmas past, present and future, warning him of the error of his ways, they'd all be identical, because he keeps making exactly the same mistake.
Since becoming Taoiseach it's as if Leo's had an ongoing bet with Simon Coveney, his own Foreign Minister, as to which of them can annoy unionists the most. For a time there Coveney was winning, as he bullishly rowed in behind Sinn Fein on every issue still separating republicans and the DUP.
Last week the Foreign Minister appeared to take a step back by accepting that fences needed to be mended with Arlene Foster's party following weeks of tension over the Irish Government's tough stance on the prospect of a hard border being reimposed post-Brexit.
"Of course there is repair work to do," he admitted.
Now the Taoiseach has apparently decided that a bit more wrecking of the North/South relationship is in order, first by explictly ruling out any return to direct rule should fresh efforts to restore power-sharing fail.
Instead, Varadkar insists that Dublin must have a "real and meaningful involvement" in running Northern Ireland if talks fall through again in the new year.
It's baffling that, after years of lecturing unionists on the need to abide by the terms and spirit of the Belfast Agreement, nationalists have suddenly decided that an arrangement that would effectively tear up that Agreement should be put back on the table.
The Belfast Agreement couldn't be clearer. The UK retains full sovereignty over Northern Ireland until a majority of the people here say otherwise. It really isn't a hard concept to grasp.
The imposition of joint authority would require a new agreement. That's not going to happen. Which is probably why Dublin isn't using the term "joint authority" to describe its demands.
Rather, the Taoiseach has been playing semantic games in calling for the "triggering of intergovernmental conferences to make decisions on Northern Ireland".
Does Leo honestly believe unionists will be fooled into accepting joint rule if he just calls it by another name?
Any such moves have previously been described by one academic as a "constitutional nightmare and politically eruptive", and that's surely putting it mildly. The bigger mystery is why the Irish Government is wrapping itself in the flag in this provocative way. Outside the Republic, it's assumed that Varadkar's Fine Gael must be worried by the electoral rise of Sinn Fein, and is seeking to head it off at the pass by playing this "greener than thou" game; but the two parties have really never fished from the same pool when it comes to votes.
That can't be it. Nor can the new appetite for antagonising unionists be explained by a need to butter up Sinn Fein for a possible coalition after the next election, or a desire to snatch votes from the more traditionally pro-nationalist Fianna Fail.
It could simply be that Dublin is so terrified of the potential impact of Brexit on the Irish economy that it's prepared to blunder down any path that seems to offer it some leverage over how the border is managed in future.
Brexit looms so large over the politics on these neighbouring islands right now that a desire to hit back at the old enemy may be winning out. Peace has allowed politicians down south to grow complacent about the dangers of provoking constitutional crises.
Ultimately, though, the real reason for the aggressive nationalism adopted by the Taoiseach and his Foreign Minister remains mystifying.
Do they have a clue how to fix this mess if it all backfires? Is there a Plan B? The schizophrenic switch from good cop to bad cop doesn't suggest they do.
And that, considering the stakes, is genuinely alarming.