If you really want to know how a magic trick is done, then stop looking where the magician wants you to look.

Ignore the spectacle and the theatre, designed to distract the audience; don’t listen to the patter, but watch what the hands are doing. And what is true for magicians is doubly so for politicians. Boris Johnson has the nation focused on the drama of a Christmas election rather than on this week’s humiliation over Brexit, but we should have learned by now to look at what the government is doing rather than what the great showman is saying.

All the overblown rhetoric about dying in a ditch rather than delaying any longer, and the chest-beating about having some secret plan to avoid asking the EU for an extension, have been exposed for the empty nonsense they were. We are not Brexiting on Thursday after all; and hot on the heels of the overwhelming relief most Britons will feel about avoiding a no-deal crashout comes a white-hot blast of rage at the time, money and energy so senselessly wasted over the last three years.

Johnson once, unforgivably, described £60m spent on inquiring into historic child abuse as money “spaffed up the wall”. So how on earth can he defend successive Tory governments blowing about £8.3bn of public money, and much of Whitehall’s collective brainpower, on Operation Yellowhammer – the no-deal emergency planning operation that lent credibility to what now look like empty threats to leave come what may?

And while it’s galling enough to imagine what else the nation could have done with those billions, that is barely the half of it. Think of all the stockpiling and worrying and understandable stalling of investment plans that businesses have done over years of being constantly nagged to “get ready” for Brexit – without ever knowing what exactly what they should be ready for. Think of all the people not hired, the expansion plans put on ice, the pay rises denied because cash had to be saved for contingencies.

Think too of all the life plans put on hold by couples worried that this isn’t a good time to start a family or move house, and the anxiety gnawing away beneath the surface of so many lives. And for what, exactly? Was any of it real, or have we all simply been pawns in a bigger game, marched up the hill and down again to lend credibility to a negotiating strategy based on threatening no deal in order to secure a deal?

There certainly are Tories deluded enough to think a no-deal Brexit is a price worth paying for their fantasy, but the evidence suggests that the prime minister isn’t one of them. He always said he would prefer a deal, ripped up his own negotiating red lines to produce one, and is probably triggering an election now, at least in part, to avoid too much parliamentary scrutiny of the difference between what he promised and what his Brexit deal delivered. (If you wouldn’t buy a secondhand car from someone who refused to open the bonnet, then don’t buy a Brexit bill from someone who threatens a snap election the minute MPs start kicking its tyres.)

Putting Operation Yellowhammer on ice merely confirms the political reality, which is that the prime minister’s bluster is no longer particularly credible either in Brussels or at home; and that in truth we have wasted untold national opportunities in pursuit of the magic beans that Vote Leave promised, only to be presented at the last minute with an opportunity to make ourselves poorer. No wonder the prime minister would rather we were all looking the other way. But there may be only so many times this particular Houdini can escape from a straitjacket of his own making.

• Gaby Hinsliff is a Guardian columnist