When President Trump returns from his Christmas break at Mar-a-Lago, he’ll face an inbox full of pressing foreign policy problems. There’s the continuing fallout from his decision to pull American troops from the Syrian border with Turkey, North Korea’s accelerating rate of missile tests, and Iran’s continuing meddling in the Middle East.

Even the good news, such as Afghanistan, where the Taliban’s ruling council has announced a ceasefire to provide a window for a peace deal, or the hopes that Washington and Beijing are about to sign a “phase one” trade deal, raise fresh questions that could yet complicate the 2020 election campaign.