Beyond the U.S. trial, here is Europe’s antitrust case against Google’s ad tech monopoly explained

As the U.S. trudges through its high-profile case against Google’s monopoly over online advertising this week, Europe is pursuing the same target – just without the courtroom drama. Time for a look at how that’s unfolding. 

Let’s start with the basics: earlier this month, the European Commission – the European Union’s executive arm – hit Google with a €2.95 billion fine for abusing its control over how ads are bought and sold in a market it also happens to run. But that was just the start. It also gave Google 60 days to come back with a fix. If it can’t – or won’t – the commission has said a breakup of Google’s ad tech business could be the only resolution.

This sounds like the antitrust case against Google in the U.S: it’s not a carbon copy of the U.S. case, but the parallels are hard to ignore. For starters, both the European Commission and the Department of Justice’s efforts trace back to the same academic groundwork: research that argued Google’s dominance stems from a built-in conflict of interest – one that wouldn’t be tolerated in most industries. In each case, the regulators came to the same conclusion. Fines aren’t working. Structural separation is the endgame. 

Any differences between the two antitrust scenarios? Yes. In Europe, the commission is in the driver’s seat. If Google fails to come up with a genuine way to wean itself off of the monopoly it has built by early November then the commission can move forward with a breakup order. In the U.S., it’s not so simple. The DOJ still has to convince a judge to do the same. That’s what this week’s trial is all about. 

Any other differences between the two? Only when it comes to what both regulators ultimately want from Google. On the European side, they want Google to rectify the harm it’s caused to the market by dint of its illegal monopoly over it. U.S. regulators want that and a way to ensure that Google doesn’t keep the spoils of their infringement of the law.

Which antitrust case will be remedied first? Technically, Europe. The commission is expected to make a decision by early November. But that doesn’t mean enforcement will be swift. Google is almost certain to appeal the decision, dragging the process out for years on either side of the Atlantic. Still, the timeline matters. Europe will be the first to show its hand. And what happens there, whether it leads to a real remedy or stalls in appeals, could shape the next phase of Google’s antitrust reckoning everywhere else.

So the Europe antitrust case will steer the U.S. one? Not exactly. These are more parallel tracks than intersecting ones. But they’re chasing the same finish line. Whether they both get there, however, is another question. Because even as regulators lay out the logic, the politics are hard to ignore. Just hours after the commission issued its fine, President Donald Trump threatened to retaliate, suggesting its penalty was unfair to American business and could justify new tariffs. Structural reform may be the legal goal in these antitrust cases, but geopolitics casts a long shadow. 

Could that derail the EU’s push? In theory, no. In practice, it’s a pitfall that can’t be ignored. Push too hard against Google’s monopoly, and the European Union risks sparking a broader geopolitical standoff – one where antitrust enforcement becomes just another front in a trade war. That could mean tariff threats, or pressure to go soft on tech regulation in exchange for keeping peace with Washington. 

Backing off, though, would be just as risky. Doing so could set a precedent that future enforcement – against Google or anyone else – can be bargained away. That sends a message not just to platforms, but to regulators everywhere. 

And yes, a precedent will be set either way: which is why this matters far beyond ad tech. The stakes here aren’t just about market share or auction mechanics. They’re about whether democratic institutions still have the leverage – and the will – to hold powerful companies accountable. That may sound lofty, but it’s where this ends up. If regulators can’t rein in the infrastructure that decides who gets heard, and who gets paid, then accountability becomes less a principle than a placeholder. 

Or as Cori Crider, executive director of the Future of Tech Institute and Honorary Professor at UCL Laws, put it in a media briefing earlier this week: “I think the basic risk is if Europeans suddenly appear to be sacrificing law enforcement on the trade table. We’re never going to be asked to do it just once. We will be asked to do it again and again.”

Wait. Didn’t a judge recently rule that Google didn’t need to be broken up to address its dominance in search? Could the same thinking apply to advertising? Not quite. In the DOJ’s case against Google’s search monopoly, it floated the idea that Google might need to divest Chrome as part of a remedy. But as the trial unfolded, it became clear that Chrome wasn’t central to the alleged conduct. The case focused instead on Google’s default search agreements – multi-billion dollar deals that ensured Google was the default on browsers and mobile devices. As a result, the court leaned toward behavioral remedies: limits on contracts and conduct, not corporate structure. 

That’s a sharp contrast with the ad tech case. Both the European Commission and the DOJ are pursuing structural remedies, specifically breaking up Google’s ad tech stack. The theory of harm here is different. Regulators argue that Google leveraged its control over multiple layers of the ad tech ecosystem – ad server, exchange and buying tools – to favor its own services, block rivals and extract rents from the open web. 

It’s less about defaults, and more about dominance baked into infrastructure. And that changes the stakes entirely. 

“The combination of dominant players, opaque bidding systems, lack of transparency and most importantly, lack of verification allows rampant fraud and the funding of an ecosystem of democratic disruption,” said Ian Moss, spokesperson of the non-profit industry coalition the U.K. Stop Ad Funded Crime group. 

Also published in: Digiday