What would push the West and Russia to nuclear war?

“The word ‘impossible’,” quipped Oleksii Reznikov, Ukraine’s defence minister, “means ‘possible in the future’.” Javelin anti-tank missiles, forbidden by America when Vladimir Putin took the first chunks of Ukraine in 2014, came in a trickle from 2017 and then a flood when he invaded again in February. Stinger anti-aircraft weapons, similarly refused, arrived in March. And the long-awaitedhimars rocket launchers have been taking out command posts and weapons dumps far behind Russia’s front lines since June. F-16 fighter jets may come one day.