Unconstrained, enterprises curdle into monopoly, innovation into rent-seeking. Today’s swashbuckling ‘disrupters’ set up tomorrow’s cosy cartels. Capitalism works when someone enforces competition; and successful capitalists do not much like competition.

Theodore Roosevelt understood this when, as US president, he deployed the Sherman Act against the industrial titans at the turn of the 20th century. Henceforth antitrust, or competition, law has served, sometimes effectively, sometimes less so, to protect the interest of consumers and thereby legitimise the profits of big business. US President Ronald Reagan, scarcely a leftie, presided over the break-up of AT&T.

Technology and globalisation have changed the game. The cross-border activities of the world’s biggest companies make it harder to map a level playing field. Globalisation has multiplied the opportunities for tax avoidance, and tax competition between states has diluted the political will to uphold competition in the marketplace.

Timid national politicians are reluctant to take on the global behemoths and their armies of well-heeled lobbyists. Yes, they would like these companies to pay a little more tax, but not so much so that they threaten to take investments and jobs elsewhere. Consumers and less privileged taxpayers are the losers. So is the market economy.

Step forward the European Commission. Margrethe Vestager, the commission’s competition chief, has been in the news lately after ordering Apple to pay €13bn in back taxes to the Irish government. If that seems like a whopping figure it should be measured against an estimated $215bn that Apple holds offshore beyond reach of tax authorities.

The cross-border activities of the world’s biggest companies make it harder to map a level playing field. Globalisation has multiplied the opportunities for tax avoidance, and tax competition between states has diluted the political will to uphold competition in the marketplace

After a lengthy investigation, Ms Vestager concluded that its labyrinthine tax arrangements with the Irish government gave Apple advantages not available to other businesses and thus undercut competition by breaching the EU’s state aid rules. The company, she said, had been paying a tax rate of just 0.005pc - though that figure is disputed by Apple, which is contesting the ruling.

The iPhone manufacturer is not the only company in the commission’s sights. Investigations are under way into the impact on competition of the tax arrangements of Starbucks, Amazon and McDonald’s. Ms Vestager is heading a three-pronged antitrust probe into the European activities of Google, a company that enjoys immense market dominance and whose tax affairs are under scrutiny in several EU member states.

It would be something of an understatement to say that these businesses are angry about the probes. The banker John Pierpont Morgan thought he could treat Roosevelt as an equal. With something of the same righteous indignation, Tim Cook, Apple’s chief executive, lambasts the European Commission’s ruling as ‘political crap’. Never mind that Apple funnels revenue though ‘stateless’ entities unaccountable to any tax authority. Mr Cook seems to believe his business operates on a higher plane than that occupied by mere politicians or regulators. Government should just get out of the way. To my mind, Apple makes stylish, clever digital gadgets, but this scarcely bestows a special status.

Google, like Apple, always insists that it is scrupulous in meeting its legal tax obligations. There is no reason to doubt its word. What this misses is that the responsibilities of business go beyond strict adherence to the statute book. The societies in which markets flourish are those that afford respect for a more complex tapestry of conventions and norms. It may be legal, say, for Google to minimise its tax bill by routing UK sales to an Irish subsidiary. It is not the act of a good citizen. And it invites a populist response. To borrow from Roosevelt: “When aggregated wealth demands what is unfair, its immense power can be met only by the still greater power of the people as a whole.”

So far politicians have been at the sharp end of the populist insurgencies across rich democracies. But behind these movements lies deep public disgruntlement with globalisation and the behaviour of big business. Whether it is Donald Trump in the US, Marine Le Pen in France or Beppe Grillo in Italy, the populist credo is economic nationalism: the system is rigged, so throw up the barricades against global capitalism.

The public perception is that the companies reaping the rewards of globalisation are beyond reach of the rules that apply to everyone else. All the insecurities of globalisation fall on ordinary citizens. Populists exploit declining faith in the marketplace. Their remedy - snake oil - is more state control.

There will always be business leaders true to the tradition of the old robber barons who think theirs is a superior calling and that democratic politics is, well, ‘crap’. They find support among libertarians and free-market literalists who believe that the only role of business is to maximise profits.

Roosevelt was no socialist. His insight was that capitalism requires legitimacy. It would thrive over the long term only if it were seen to be on the side of the welfare of the nation’s citizens. This is as true now as it was then. It is too soon to pass Roosevelt’s mantle to Ms Vestager. But everyone who supports the liberal market economy that made possible the success of Apple, Google and the like should be applauding her courageous effort to reset the balance.

philip.stephens@ft.com

Published in Dawn, Business & Finance weekly, September 19th, 2016