“A far-off country of which we know little” was Neville Chamberlain’s argument for doing nothing about Hitler’s 1938 annexation of Czechoslovakia. That annexation – carried out by a revanchist Nazi regime, allegedly in defence of ethnic Germans, is an unnerving parallel to Vladimir Putin’s annexation of Crimea. Russia’s president is using ethnic Russians as an excuse to restore Moscow’s old empire. Viktor Yanukovich, the ousted president of Ukraine, has even said: “I would like to ask those who cover for these dark forces in the west: are you blind? Have you forgotten what fascism is?” I really do hope not.

The west is not going to war with a nuclear-armed Russia. But outright annexation of a part of a smaller country strikes at the roots of the post-second world war European settlement. Angela Merkel, Germany’s chancellor, was right to say that Russia had resorted to the “law of the jungle”. This annexation cannot go unanswered. It is too dangerous a precedent.

Some argue that the west has already created the precedent by separating Kosovo from Serbia. But that was a response to Serbia’s brutality. Nothing like that had happened in Crimea. Nor did any western power annex Kosovo. A far better parallel is between Serbia’s actions in Kosovo and Russia’s forgotten brutality in Chechnya.