There is a growing confidence in the western alliance about the course of the war in Ukraine. That confidence is both justified and potentially dangerous.

The invasion has gone far worse for Russia than most people dared hope in the west. The western allies have surprised even themselves with the strength, speed and unity of their response — with unprecedented sanctions imposed on Russia and military aid poured into Ukraine.

The increasingly bullish mood in Washington and parts of Europe was reflected in Joe Biden’s controversial remark that Russia’s Vladimir Putin “cannot remain in power”. The US president is widely assumed to have spoken in an ill-considered way that his aides had to swiftly walk back. But his comments reflect a sense in Washington that some form of “regime change” in Russia is both conceivable and desirable.