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.

Since the shah’s ouster in February 1979, Iran’s Islamic regime has been propelled by Ayatollah Khomeini’s revolutionary vision and underpinned by its animus toward the United States.

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