Vladimir Putin launched his invasion of Ukraine 100 days ago by threatening countries tempted to interfere with consequences “such as you have never seen in your entire history”. Russian television has since tantalised viewers with chit-chat about nuclear Armageddon. 
 
The moral revulsion that restrains the use of nuclear weapons has been weakening. Weapons are proliferating. As memories of Hiroshima and Nagasaki fade, there is insufficient alarm at the prospect of how hard it will be to keep the peace if many states have a bomb. The invasion of Ukraine adds to this malaise. Russia is unlikely to use a nuclear weapon in Ukraine. But Mr Putin’s threat has prompted NATO to limit the support it is prepared to offer the government in Kyiv. Some have warned that inflicting a defeat on Russia could back its president into a corner with devastating consequences.
 
One implication of this is that vulnerable states that see the world through Ukraine’s eyes may feel that the best defence against a nuclear-armed aggressor is to have weapons of their own. The other is that nuclear-armed states may believe that they can gain by copying Mr Putin’s tactics. One day someone somewhere will surely turn their threat into reality. That must not be this war’s devastating legacy.

Russian forces captured parts of Severodonetsk, a town in Ukraine’s eastern Donbas region. Some Ukrainian defenders were holding on, but many of the 10,000 thought to have been stationed there retreated. Russian troops have been advancing slowly in the east of the country, assisted by heavy artillery.

America said it would send more weapons to Ukraine, including long-range rocket launchers that will help the country’s defenders shoot back at the Russian artillery pounding their positions in the east. The Pentagon is supplying the new kit on condition that it not be used to strike targets in Russia. President Joe Biden reiterated that America does not seek war with Russia, and does not aim to oust Vladimir Putin, Russia’s president.

The euro zone’s annual inflation rate leapt to 8.1% in May. The European Central Bank is expected to raise interest rates for the first time in a decade in July and again in September. Surging prices may mean that it will opt for bolder increases than currently envisaged, perhaps of half a percentage point.