Do US workers lose their jobs when goods are imported?

These days everybody seems to be talking about NAFTA.

The North American Free Trade Agreement.

It is a free trade deal between three countries: Canada, United States and Mexico.

It's one of the most significant trade deals Canada has ever signed.

It's also at risk of being ripped up by this guy.

We have NAFTA which is a total and complete disaster.

Basically, Trump says NAFTA is a rotten deal for the United States, he wants to fix it or nix it.

But before we get into all that, let's back it up.

The idea of free trade has been kicking around for decades.

On our strength and growth depends the strength of others, the spread of free world trade and unity.

Even hundreds of years.

Foreign trade is the key to prosperity.

Free trade will bring on a great depression.

But by the 1980s people in Canada were pushing for a full-blown free trade deal with the United States.

Some worried that free trade with the States would kill jobs in Canada, and even erode our political independence.

The 1988 federal election was actually fought on this issue.

The conservative government of Brian Mulroney promised to sign a free trade agreement with the United States.

I believe that in my own modest way, I am nation building because I believe this benefits Canada and I love Canada.

Mulroney won.

Free trade became a thing, and a road was paved for a broader deal that pulled in Mexico.

Thus, six years later NAFTA was born.

Fast forward to now.

3.5 billion dollars in trade, flows among the three countries every single day.

There was more than 750 billion dollars in trade between Canada and the US last year.

That makes the US by far Canada's biggest trading partner.

None of this was too controversial until Trump came along.

NAFTA, remember NAFTA what it's done to this country.

He blame NAFTA for gutting US manufacturing, and said American workers were getting ripped off.

True to his word, he wants to renegotiate the deal, and says that if he doesn't like it, the US will pull out.

So here we are, renegotiating a trade deal that props up hundreds of billions of dollars in trade each year.

What can we expect to happen?

For Canada there are a few sticking points.

The Americans want to sell more of their dairy products in Canada, but that would mean tinkering with Canada's long standing measures to protect our dairy industry.

A system called supply management.

The politicians have repeatedly promised to protect over the years.

There's also an American demand to remove an international dispute resolution panel from the agreement.

So that US companies claiming them being mistreated can have their cases heard in an American courtroom.

It's a complicated thing, but the bottom line is this: The Canadian government doesn't want NAFTA to be killed.

But assuming it survives, what it looks like after this renegotiation, and how that affects the Canadian economy remains to be seen.

For the Toronto Star, I'm Alex Ballingall.