OTTAWA — Nothing has reshaped Canada’s modern economy more than free trade with the United States.

But that doesn’t mean the country is staring at economic ruin if the current negotiations over the future of the North American Free Trade Agreement collapse, and the agreement is scrapped.

Prime Minister Justin Trudeau is just one among many Canadians who have suggested that the trade deal is far from critical to the country’s economic survival.

“We will not be pushed into accepting any old deal, and no deal might very well be better for Canada than a bad deal,” Mr. Trudeau said in Chicago this month. His government supports Nafta, but it has rejected many of the demands put forth by the Trump administration as conditions for keeping the three-country trade pact, to which Mexico also belongs.

The prime minister’s remarks may have been a negotiating tactic. But many trade experts say the changes to the world’s trading system that have come about since Canada and the United States opened their mutual border in 1989 mean that an end to Nafta would not be a devastating blow to the world’s 10th largest economy.