By suspending Parliament and promising to resign, the prime minister bought the Liberals time. But Canada will now face Donald J. Trump with a lame duck in charge.

Justin Trudeau has been Canada’s prime minister since November 2015, longer than any other leader of a major western democracy. But a series of political fumbles — including the scathing resignation of his finance minister,

C anadian Prime Minister Justin Trudeau is stepping down as the leader of the ruling Liberal Party, following months of pressure from partymates to resign amid increasingly poor public approval ratings.