A Meeting Postponed, Not (Officially) a Relationship Severed
On September 4, 2026, the Wall Street Journal reported that Lynda Marshall, chief of the DOJ Antitrust Division's international section, had emailed staff earlier that week directing them to halt cooperation with Canadian competition authorities — both on active cases and on policy engagement — without giving a reason. The DOJ pushed back hard. Spokesperson Kiersten Pels called the WSJ's characterization "false," adding: "What was relayed was to temporarily hold off on a scheduled meeting on a specific investigation until the DOJ's antitrust team had more time to prepare." Even on the DOJ's own account, then, at least one scheduled meeting on a specific case was shelved — the dispute is over scope and motive, not whether something changed.
The timing is not subtle. The U.S. imposed 50% tariffs on roughly $20 billion of Canadian goods on August 22, 2026, after trade talks broke down, and Canada answered on September 8 with retaliatory duties of 15% to 50% on a comparable slate of American exports. A trade war escalating by the week is the backdrop against which an antitrust cooperation channel — historically among the most technocratic, insulated corners of the bilateral relationship — reportedly went quiet.
Two Governments, One Company, Two Ad-Tech Cases
The reason this matters beyond diplomatic optics is that both countries are, right now, litigating strikingly similar cases against the same company. On September 2, 2026 — two days before the WSJ story broke — U.S. District Judge Leonie Brinkema issued her remedies ruling in United States v. Google (E.D. Va.), the ad-tech monopolization case. She declined the DOJ's request to force Google to divest its AdX exchange or DFP publisher ad server, reasoning that a breakup could hurt small publishers dependent on the free tools and that predicting a five-years-out market is inherently uncertain. Instead she ordered a set of behavioral fixes: real-time bid data must be shared with rival ad servers, Unified Pricing Rules are being deprecated, publishers get more control over price floors, and Google's "first look" and "last look" bidding advantages are eliminated.
Canada's Competition Bureau is pursuing a parallel but more aggressive case. Its application, filed with the Competition Tribunal on November 28, 2024 after an investigation opened in 2021 and expanded in February 2024, alleges Google holds a 90% share of publisher ad serving, 70% of advertiser networks, 60% of demand-side platforms, and 50% of ad exchanges in Canada — with more than 200 billion Canadian web ad transactions flowing through Google's tools in 2022 alone. Unlike Judge Brinkema, the Bureau is still asking the Tribunal to order Google to sell DFP and AdX outright, plus a penalty of three times the calculated benefit of the alleged conduct or 3% of Google's global revenue if that benefit can't be pinned down. Google's constitutional challenge to those penalties — arguing they amount to disguised criminal punishment — was dismissed by the Tribunal on March 4, 2026, clearing the case for trial.
The Case for Keeping Enforcers Talking
There's a real argument for tight U.S.-Canada antitrust coordination here, and it deserves to be stated plainly rather than waved off. Parallel proceedings against the same conduct create genuine risks of inconsistent factual findings, duplicated discovery burdens on both the company and the agencies, and remedies that conflict with each other — a divestiture ordered in one jurisdiction could complicate a behavioral remedy negotiated in another. Cooperation also lets smaller enforcers like Canada's Bureau draw on the evidentiary and economic groundwork a bigger agency like DOJ has already built, which is a legitimate efficiency gain, not mere deference.
Why Trade Leverage Doesn't Belong Here
But the Bureau's Google case doesn't depend on DOJ's goodwill — it proceeds under Canada's own Competition Act, before Canada's own Tribunal, regardless of what happens on the tariff front. That independence is exactly the point: antitrust enforcement is supposed to be one of the areas where legal predictability outranks the news cycle of a trade dispute, because businesses — and enforcers — need confidence that a competition case won't become a bargaining chip. Even a single postponed meeting on a live matter, confirmed by the DOJ's own spokesperson, sets a precedent that international enforcement cooperation is conditional on unrelated trade concessions. That cuts against everyone, including U.S. firms that benefit from predictable, apolitical enforcement abroad.
The underlying substance also argues for keeping the channels open rather than shutting them: Judge Brinkema's preference for behavioral remedies over a breakup reflects the kind of proportionate approach this publication has consistently favored — one that disciplines dominant conduct without destroying the free tools smaller publishers rely on. Canada's Bureau, still pushing for structural divestiture, would benefit from exactly the kind of technical exchange with DOJ that a trade-driven freeze puts at risk. Keldon Bester of the Canadian Anti-Monopoly Project noted after the March ruling that "financial penalties will always be secondary to structural remedies that promote competition" — a debate about remedy design that two allied enforcers should be having together, not past each other.