What would push the West and Russia to nuclear war?

‘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-awaited rocket launchers have been taking out command posts and weapons dumps far behind Russia’s front lines since June. -16 fighter jets may come one day.America and Europe hail Ukraine’s fighting spirit, which raises a nagging question: why are they not sending more weapons, more quickly? The latest $1bn American military package for Ukraine includes munitions for but no more launchers beyond the current 16, which many experts think insufficient. Officials’ answers vary: the West is giving priority to weapons that are most urgently needed; it has to train Ukrainians to use and maintain their new kit; and they have to show they can use it effectively in battle.