The ongoing contract talks between the Detroit 3 and Canada's Unifor union expose a real dilemma.

If there has been a loser since that country, the U.S. and Mexico agreed on the North American Free Trade Agreement, it has been Canada.

The production of Detroit 3 vehicles there has dwindled since 1994, and if left unchecked, the number will quite likely continue to fall. Because there are no tariffs between the countries, we have seen a huge investment in Mexico by each of the Detroit 3 as well as their overseas rivals.

Now the Canadian union is putting its foot down and saying no more. It wants the promise of new products and guarantees to keep the same number of jobs in the future without losses. That makes it difficult for Ford, General Motors, Fiat Chrysler and their suppliers in North America.

Mexico is getting most of the growth, with automakers announcing Mexican investment plans worth more than $24 billion since 2010, according to one study.

Although Donald Trump has made Ford the target of his barbs, I am sure the UAW will weigh in on the issue shortly, particularly after the presidential election.

For the UAW in the United States, it has been a bitter pill to swallow to see that much investment outside the U.S.

Today the auto companies are going to have to come to grips with the unions in the U.S. and Canada. That will be difficult and delicate as well.

The tentative GM contract that Unifor's members were scheduled to vote on Sunday, Sept. 25, includes pledges of new investment. If GM is able to keep Unifor happy, GM will have to make sure that it keeps the UAW happy -- an interesting balancing act. UAW President Dennis Williams has already said that he considers the system broken. But as with Humpty Dumpty, it will be a challenge putting it all together again.

And if Trump is elected president, everyone will have to worry about a renegotiated NAFTA, something that was signed during Bill Clinton's first term.

It is a real mess with no easy solutions. It doesn't look like there are going to be any big winners, just a lot of change -- and no chance for the Trans-Pacific Partnership.