Who else will buy some of those items if they stop selling a good amount to US,
China, Japan, South Korea, Caribbean countries and anyone else in the world.
Oil is a fungible commodity.
Meaning anyone will buy it and it is interchangeable with the same product from other places in the world.
The major difference is the level of sulfur in the oil.
There are refineries that purchase Canadian oil because it is CHEAPER than all the other oil produced in the world.
Do you pay more for gasoline and drive 30 miles out of the way to buy it?
No, you buy it from the place that is convenient and the least expensive.
This is WHY we buy things from Canada.
They are right next door which lowers the freight to get it here.
Which makes it cheaper than oil from other sources.
This is the same reason why we buy their paper products, lumber, aluminum, steel, diamonds, minerals, seafood and lots of other products.
They are delivered cheaper than other comparable products.
That is how the Free Market works.
When you add Duties, Tariffs, Quotas to the market it changes the price delivered.
Typically increasing it for the final consumer, YOU.