JEREMY CORBYN might still need some convincing, but the rest of the Western world appears to back Prime Minister Theresa May’s assessment that the Russian state was responsible for the poisoning of Sergei Skripal and his daughter, Yulia, in Salisbury earlier this month.

Yesterday’s coordinated expulsion of Russian diplomats stationed in 17 different countries represented an unprecedented display of unity in the face of sustained aggression from Moscow.

The United States’ decision to expel 60 envoys was especially significant, with Donald Trump having previously been accused of failing to take a hard enough line against the Kremlin. Finally, the US president appears to have concluded that Vladimir Putin is not to be trusted.

The Russian foreign ministry has already promised a “strong reaction” to an “unfriendly act”, and on the back of its annexation of Crimea and ongoing military action in Syria, Russia’s relations with the West are currently more strained than at any time since the fall of the Soviet Union.

That is clearly alarming, but a flagrant act of poisoning committed on British soil cannot be allowed to go unpunished.

Russia has been acting with impunity for far too long, and the muted international reaction to the murder of Alexander Litvinenko in 2006 almost certainly played a part in paving the way for this month’s attack.

A public inquiry into Mr Litvinenko’s death concluded that President Putin “probably approved his assassination”, yet the wider world did nothing.

This time, Russia’s actions have not gone unpunished, and while it would be naïve to assume President Putin will start adhering to international law, at least he now knows that his actions do have serious consequences.