Canada’s banker-turned-prime-minister pulled off a political miracle, leading his party from polling abyss to a rare fourth term in power, and securing the top government job after entering electoral politics just three months ago.

Mark Carney, the country’s new leader, told Canadians that he was the right person to stand up to President Trump and that, with his economics expertise, he knew how to boost the country’s lackluster economy and fortify it in turbulent times.

Now he has to actually do all of that, and quickly, as his country moves from a prolonged period of political turmoil and faces the fallout of a trade war with its closest ally and economicpartner: the United States.

Mess at Home

When Mr. Carney’s predecessor, Justin Trudeau, announced in January that he would resign after 10 years leading Canada, he created a rare opportunity that Mr. Carney jumped at.

But after Mr. Carney won the race to replace Mr. Trudeau in March as prime minister and leader of the Liberal Party, he also inherited a messy situation at home that he must now urgently take on.

The Canadian Parliament has not been in session since before Christmas, after Mr. Trudeau suspended its activities to be able to hold the Liberal leadership election that elevated Mr. Carney.