The C$6.4bn Gordie Howe International Bridge, built to unclog the busiest trade corridor between Canada and the United States, will open to traffic on Monday without a bilateral inauguration. In a gesture of diplomatic displeasure, Ottawa disinvited American officials from Friday’s ceremony in Windsor, Ontario, after President Donald Trump abruptly threatened 50% tariffs on Canadian goods. The move caps months of friction over a span meant to embody transnational cooperation and inject competition into a crossing long dominated by the privately owned Ambassador Bridge.

At the heart of the row is a revised tolling arrangement disclosed by the Windsor-Detroit Bridge Authority. Under the original 2012 compact with Michigan, Canada — which financed the entire project — was to retain all tolls until it recouped its debt, after which revenues would be split with the state. Washington, however, blocked the opening this spring, with Trump demanding “shared authority and ownership.” To unblock the bridge, Ottawa agreed to pay 50% of net operating revenues into a U.S.-controlled economic development fund for 15 years, a concession Trump touted as “MUCH BETTER” for America. Canadian officials stress that the underlying Michigan deal remains untouched, meaning no revenue will flow to the state until Canada’s costs are repaid, likely decades off.

Prime Minister Mark Carney, who had earlier insisted no tolls would be shared before debt repayment, acknowledged he “could have explained it better” and that the short-term revenue split does not include debt-servicing costs. Opposition Conservatives call the sequence a climbdown. MP Shuvaloy Majumdar characterised it as “a series of successive concessions” that leave Canada “vulnerable to the improvised negotiations of an aggressive U.S. administration.” Conservative MP Kelly McCauley, chair of the government operations committee, will convene a hearing on 29 July to probe the deal. Ontario Premier Doug Ford, by contrast, praised Carney for getting the bridge open, citing $300bn in annual cross-border trade and Michigan’s role as Ontario’s top partner.

Viewed from Detroit, the new six-lane, 2.4km span breaks the monopoly of the Ambassador Bridge, which carries over a quarter of all Canada-U.S. trade. The billionaire Maroun family, owners of the Ambassador and reported donors to Trump, had long opposed the project; Michigan media note that Matthew Maroun met with the U.S. commerce secretary shortly before the president’s intervention. Windsor Mayor Drew Dilkens called the collapse of joint celebrations “regretful” but expressed hope for better times. The dispute unfolds within a wider trade confrontation: Washington has linked new tariffs to provincial alcohol bans and to Canadian wildfire smoke, while Carney’s government has already suspended a digital services tax and lifted some retaliatory levies.

The bridge will therefore open not with a handshake but with a solo Canadian ceremony, a symbol of a relationship that, according to former diplomat Colin Robertson, resembles “dealing with pirates” who “renege on deals.” For now, goods and vehicles will flow, but the political dossier remains open, with the committee hearing and broader trade talks promising further chapters.