The trade confrontation between Washington and Ottawa highlights a fundamental contradiction: the United States seeks to reduce its trade deficit with Canada while relying heavily on Canadian oil. In 2025, Canada supplied US refineries with around 3.9 million barrels of crude per day, more than 60% of US crude oil imports. Hydrocarbon trade is therefore central to economic relations between the neighbours, far more than the tariff debate alone suggests.
This dependence reflects the structure of US refineries. A substantial share of facilities, particularly in the Midwest and on the Gulf Coast, is designed to process heavy crude. Canadian oil, transported mainly by pipeline, meets these industrial needs. Rapidly switching suppliers requires logistical adjustments, trade-offs between crude qualities and sometimes additional operating costs.
Alberta is central to this relationship. The province accounts for most Canadian oil production and sends large daily volumes to the United States. The Trans Mountain pipeline provides a Pacific route, but its capacity remains far below flows destined for the US market. For Canadian producers, the US outlet therefore remains decisive; for US refiners, Canadian crude is part of their regular supply.
Tariffs do not stop at the border
An energy export tax or retaliatory measure might appear to give Ottawa negotiating leverage. It could nevertheless raise costs for US refiners and consumers while reducing Canadian producers’ revenues. Interrupted flows would not automatically result in simple, immediate replacement with crude from elsewhere. Refineries must maintain blends compatible with their facilities and final product qualities.
The price effect would depend on the disruption’s duration and scale, available stocks, alternative pipeline capacity and the ability to import comparable grades. Although the United States is among the world’s leading producers, abundant production does not mean complete independence for every region or refinery. Its energy system remains organised around specialised cross-border flows.
Canada also faces constraints on outlets. Production is located far from several export ports, and pipelines determine economically accessible destinations. Trans Mountain’s expansion improved Pacific access, but the United States remains the most integrated and often easiest market to serve. A prolonged dispute could therefore weigh on prices received by Canadian producers, particularly if capacity to the coast or other markets cannot quickly absorb redirected volumes.
Keystone XL: political promises and infrastructure realities
Reviving Keystone XL is regularly discussed as a way to increase transport capacity for Canadian oil to the United States. The initial project was intended to carry up to 800,000 barrels per day, but faced political controversy, regulatory proceedings and local opposition. A new announcement or presidential signal cannot automatically restore the permits, transport contracts and financing agreements required.
For a pipeline to be built, shippers must commit to using capacity for a sufficient period, developers must secure capital and authorities must address routing, environmental and safety issues. The prospect of an investment decision in 2027 therefore remains a milestone to watch, not a certainty. If the project progressed, it would increase Canadian export options to the south, but also strengthen the energy interdependence that a tariff war sometimes claims to reduce.
Existing pipelines illustrate the same logic. They connect producers, transport operators, refineries and consumers through contracts and supply chains that cannot be reorganised overnight. Tariffs can alter prices and margins, but do not instantly create new routes or refining capacity.
An energy relationship that withstands political rhetoric
Oil represents a considerable share of Canadian exports to the United States. Trade data show that excluding crude would produce a very different bilateral trade balance for both countries. This reality gives energy a central role in negotiations, but participants’ interests differ. Producers want reliable outlets, refineries seek suitable feedstocks and governments may want to use energy as political leverage.
A policy seeking to reduce imports without considering refinery needs can create pressure on costs and refined product prices. Conversely, excessive dependence on one route or supplier exposes both economies to outages, disputes and regulatory decisions. A lasting response requires resilient infrastructure, predictable coordination and dispute resolution mechanisms.
The Canadian case shows that a trade war between integrated partners often imposes shared costs. The United States can seek diversified supply, but quickly replacing several million barrels per day would be complex. Canada can seek new markets, but transport capacity remains decisive. Oil does not erase political disagreements between the capitals; it simply makes their economic cost more concrete.