These are fraught times, and while you may be scared, Tim Wu suggests that you may not be scared enough. Like Michael Lewis’s “The Fifth Risk,” a recent book that shows how something most people don’t spend a lot of time thinking about — government bureaucracy — is consequential (and potentially terrifying), Wu’s “The Curse of Bigness: Antitrust in the New Gilded Age” is a surprisingly rousing treatment of another presumably boring subject: mergers and acquisitions.

Wu, a professor at Columbia Law School and a contributing opinion writer for The New York Times, argues that the M&A arcana that lawyers and economists haggle over have effects that spill far beyond their rarefied areas of expertise. “Extreme economic concentration yields gross inequality and material suffering, feeding an appetite for nationalistic and extremist leadership,” he writes, by way of introduction and warning. “The road to fascism and dictatorship is paved with failures of economic policy to serve the needs of the general public.”

Unlike Wu’s previous books, “The Master Switch” (2010) and “The Attention Merchants” (2016), “The Curse of Bigness” is skinny, more of a dip with a snorkel than a deep dive. But the pithiness of this new volume is ideally suited to its subject. Wu doesn’t want to get into all the intricacies of antitrust law; if anything, an enormous book on the problem of enormity would only fool us into believing that the subject is more impenetrable than it really is — and stoke the confusion and apathy that have allowed decades of corporate consolidation to flourish in the first place.

Wu’s point is simple. Giant corporations, seeking to protect their advantage, try to turn their outsize economic power into political power. So to break their grip on American democracy, the government needs to break them up in turn. That this proposal might sound outrageously radical to certain ears is, Wu says, just one sign of how unprepared we are for our current moment. To show how busting up big businesses into smaller parts was once a veritable American tradition, he charts how antitrust law emerged in response to the grotesque inequality of the 19th-century Gilded Age.