So once again we'll go to a Tribunal/Court, Canada will win, the US will be obligated to pay back the collected Tariff with Interest.
Not always, I see only once that the US returned 4 out of 5 billion.
http://www.vox.com/policy-and-politics/2017/4/25/15419854/trump-canada-lumber-trade-war
It really started to heat up, though, in 1982, when the American lumber industry first asked the Department of Commerce to take action against Canadian sawmills. They said the Canadian government was unfairly subsidizing Canadian lumber companies, and that, in turn, was hurting American sawmills.
The Commerce Department rejected those claims.
But the second time around, in 1986, the lumber industry succeeded. Commerce prepared to levy a 15 percent tariff on imports. It never happened because both countries came to an agreement:
Canada would impose a 15 percent tariff on softwood lumber exports. That lasted a few years,
until Canada decided to back out of the agreement in 1991, arguing that it had raised logging prices for Canadian companies.
The US timber industry, which employs about 90,000 people, fought back once again and filed a claim with the Commerce. After back-and-forth negotiations,
both countries came to an agreement in 1996, which set a quota on Canadian lumber imports to $14.7 billion a year, tariff-free.
That led to a third case before the Commerce Department, which eventually led to a
five-year trade deal in 1996 that merely limited Canadian lumber imports to $14.7 billion per year. That deal expired in 2001.
But in
2002, the Commerce Department levied a 27 percent tariff on Canadian lumber, and
Canada took the case all the way to the World Trade Organization. After years of arguing, the two countries finally reached a deal in 2006.
The United States returned $4 billion (out of the $5 billion) in tariffs it had collected from Canada since imposing the tariff in 2002.
In return, Canada began restricting its lumber exports again. As part of the deal, US timber producers couldn’t file any more cases until one year after the deal expired, which was in October 2016.