The conference in Poland will be a major test of the world’s collective political will to fight global warming. Following through on promises made in Paris will not be easy.

A collapse of this Cold War–era INF treaty, which many believe has favored the United States, could unleash a new age of nuclear weapons competition with Russia.

The United States has been helping Somalia fight al-Shabab militants for more than a decade, but rights groups say increasing drone strikes are putting civilians at risk.

Iran appears increasingly boxed in by intensifying U.S. sanctions, the latest of which will effectively cut it off from its main oil customers.

Neither Iran nor the United States likely wants war, but the possibility of a miscommunication is considerable, risking a dangerous escalation.