The Western world is in the throes of a populist revolution — or at least an attempted populist revolution. Populists have swept the polls in the U.K., the U.S., Poland, Hungary, and now Italy. And ... it hasn't gone according to plan.

It's past time the populists hired some wonks.

To understand why, take two recent examples.

On Brexit, U.K. Prime Minister Theresa May has agreed to something called "the backstop," which essentially means the U.K. will stay in the EU's single market indefinitely until it figures out how to leave without closing its border between Northern Ireland and the Republic of Ireland. This is important because keeping that border open was part of the settlement that ended the Troubles. But you see the problem: If the U.K. leaves the EU and its single market, then Northern Ireland (which is part of the U.K.) will be in one economic area, and the Republic of Ireland (which is independent and part of the EU) in another, which will potentially mean they would need a border, with border checks. Which nobody wants.

The Northern Ireland border issue is one of the trickiest parts of Brexit. But what makes it especially difficult is the sense that nobody in the Brexit camp had even given it much thought until after the referendum.

For the second example, take this recent Times story on Trump's trade negotiations, relaying how business groups tried to get meetings with Trump's trade teams, only to find themselves sending emails and making phone calls into the void. Trump's trade team is riven by infighting as hawks and doves try to set the terms of the debate.

It's all the sadder given that, on the merits, the Trump hawks are more right than wrong on trade. Behind closed doors, even establishment types admit that the U.S., and the West more generally, is getting robbed blind by China on trade, and that something should be done about it.

Issues like Brexit and trade bring to mind the famous-to-history-nerds quip by Lord Palmerston, 19th century British statesman, on the Schleswig-Holstein Question, an obscure point of international law that Prussia used as a pretext to declare war on Denmark: "Only three people have ever really understood the Schleswig-Holstein business — the Prince Consort, who is dead — a German professor, who has gone mad — and I, who have forgotten all about it."

Populist movements have gotten many things right. We do need to rethink free trade. We do need a better foreign policy model. I think immigration is generally good, but Europe simply throwing open its doors to millions of migrants overnight was insane and will probably have negative consequences down the road. And, yes, political correctness has gotten out of control.

But one thing that too many populists are definitely wrong on is the idea that principles, even excellent ones, are good enough to right the ship of state. Issues like Brexit, trade deals, regulatory policy, and taxes are complex. Understanding them and working them out is a job, and a complicated one.

And, look, I get it. Yes, the cult of expertise has done a lot of damage, and yes, "we know what we're doing" has too often been used as a fig-leaf for a mix of blind arrogance and blatant trough-feeding. Fake expertise is bad! But that doesn't mean all expertise is bad.

I can agree with you that the pilot is flying the plane in the wrong direction. I can agree with you about where the plane should be headed. It would still be a good idea if you took flying lessons before you got into the cockpit.

Brexit is a perfect example of this. The reason why Brexit is such an amazing opportunity for Britain is also what makes it so terrifying. Britain wrenching itself free from the grip of Brussels will give it a blank page on so many issues that were ruled by European law. In so many areas, it will be able to start fresh. That means that tens of thousands of pages of legislation and regulations will have to be rewritten. By whom? Not by skilled euroskeptics, because there simply aren't enough of them to go around. In all likelihood, they will be written by lobbyists or bureaucrats. Or bureaucrats-turned-lobbyists.

Or take the two-steps-forward-one-step-back quality of Trump's trade non-negotiations. The problem isn't just Trump's temper. It's that there were so few trade hawk candidates to staff the administration that they had to fill many spots with doves, leading to the predictable bickering and infighting and the promotion of dolts and grifters.

The point is this: Populist movements have spent countless amounts of money and energy on things like political mobilization, new media platforms, and so on. Great! But if they want to actually change the world, and not just win one election and then get kicked out, there's another thing they should invest in: wonks.

Yes, policy experts and pointy-heads. And those ghastly things, think tanks. Armies of them. I know they seem useless to you, but learning that you're wrong might be the most expensive lesson of your lifetime. You need people with genuine ideological commitment to your ideas as well as actual expertise to man those ministries and departments and agencies.

Otherwise, the ship will run aground. And no matter how many elections you win, the establishment will win in the end.