Theresa May's strategic error on Article 50 was a much bigger mistake than her decision to call an early election

Here in the UK, the June 8, 2017, snap election is currently regarded as Theresa May's most serious blunder. She snatched defeat from the jaws of victory by misjudging the connection between the crumbling economy and the willingness of voters to continue supporting the government in charge of it.

But in the long-run — as Barnier's quote implies — history will judge the decision she made in October 2016 as much more seriously wrong than the election: That was when she announced she would formally trigger Article 50 in March 2017. The notice conveniently gave the EU six months warning of what was to come. At the same time, it locked Britain into an impossibly tight schedule to prepare its case.

16% of our time has already run out

The precise timing of the trigger is crucial because the negotiation deadline in Article 50 is more important than the substance of the talks themselves.

There's a good test for this: The clock, as Barnier says, is ticking. It only lasts 24 months. We're already 4 months in. Sixteen percent of the sands in the hourglass have already run through. What has Britain achieved so far?

Not much!

That's why Barnier is so happy to respond to Foreign Secretary Boris Johnson's vague threats about the UK not paying its EU bills. Time is on his side.

This isn't a game that Britain can win. And it is not clear that May understands that, judging by her October decision.

It is to the EUs advantage to just let the clock run out

The two-year clock in Article 50 controls the entire negotiation: Any member of the 28-nation bloc that triggers it is automatically ejected from the EU with or without a deal after two years. It can only avoid the two-year deadline if it agrees to a humiliating reversal or obtains a highly unlikely extension to the negotiation period. (The law is currently unclear on whether Article 50 is irrevocable.)

The most important thing is that the EU has no interest in giving Britain a good deal. Quite the opposite: The EU is incentivised to demonstrate to other European countries that exiting EU leaves you in a worse position than staying inside it. So it is actually to the EU's advantage to not negotiate at all, and just let the UK flop out of the EU with no deal. "No deal" is the least advantageous position for Britain, because it comes with no formal access to the European market.

Once Article 50 is triggered, the EU can run out the two-year clock, until Britain is ejected in a "hard Brexit" without any of its demands or requests being met.

Given all that, May's best strategy would have been to try her hardest to start informal — or even secret — negotiations and get an exit agreement in principal before pulling the trigger, making the Article 50 trigger itself a mere formality.

That would have been difficult to do. The EU's official position was to talk to the UK until after the trigger is pulled.

But it was not impossible. The "no prenegotiations" stance is a principle, not law. There is nothing in the text of Article 50 that prevents negotiations from beginning, or even concluding, before Article 50 is triggered. The law says nothing about when the talks should take place. May could have delayed the trigger while her troops buttonholed EU officials into some sort of preliminary agreement. Instead, she went in blind.

Britain cant stop the clock

The EU knows that the two-year clock is now ticking loudly. The period can be extended, but only by unanimous agreement. The UK cannot unilaterally extend the deadline.

The EU negotiations are so big and so complicated that there is no way the UK will have a free trade deal in place before the end of the two-year period. It might be doable in seven years. More likely 10. But not two.

So May entered Article 50 with the odds against her: She had no informal agreement going in, she has an opponent who controls the clock, and the time is too short for her to get the best deal.

Let's hope she has something up her sleeve we don't know about. Because right now, history will judge her much more harshly for triggering Article 50 than it will for calling the election.