Guns, drugs and migrants: Biden heads to Mexico to face diplomatic challenges with North American allies

When North American leaders gathered in 2021 — at the first summit for the group in five years — the mood was upbeat. Gone was former President Donald Trump, who came to power demonizing Mexican migrants and who once called Canadian Prime Minister Justin Trudeau “very dishonest and weak.”

But as President Joe Biden takes part Monday in what’s informally known as the “Three Amigos” summit, the camaraderie has begun to fade, and the post-Trump honeymoon appears to have ended.

Differences over trade practices and crime have grown steadily more...