“The cold war is back with a vengeance and a difference,” Guterres said. The difference is that it is no longer cold. American troops are already a grenade’s toss away from Russians and Iranians in Syria, and this weekend, missiles and planes from the US, UK and France flew at the Syrian regime.

It was Russia Trump warned to “get ready” for incoming missiles after the Douma chemical weapons attack, and Russia he warned would pay a “big price” for betting on Assad. If an unforeseen and unplanned clash takes place, the commander-in-chief’s state of mind is critically important. The absence of any check in the nuclear launch protocol that would allow any other US official to countermand a direct presidential order remains arguably the world’s scariest fact.