Words have not been enough.

Faced with Russia's belligerent behaviour in the Ukraine, the European Union's decision to impose targeted sanctions on 21 Russian and Crimean officials is, on balance, right. International criticism appeared to be having no impact on the Kremlin. If Russia is permitted to annexe Crimea without challenge, other expansionist moves could follow. Starting with asset freezes and travel bans affecting key figures and leaving open the threat of further sanctions, the EU, in tandem with the US, is putting Moscow under pressure but leaving it room to change course. At least, that is the theory.

The events to have unfolded in Ukraine in the last month are complicated but Russia's actions are to be deplored. Moscow has exploited internal turbulence in Ukraine to promote its territorial ambitions, disingenuously refusing to acknowledge any links to the pro-Russian forces controlling Crimea. It has shown a reckless disregard for the now very serious threat of war on the peninsula.

Dissenting voices rightly interject that there are problematic issues for the West in supporting the Ukrainian regime and opposing Crimea's secession. Viktor Yanukovych, the legitimately elected president of Ukraine, was ousted by an uprising; among the mob were far-right nationalists (hence Russia's characterisation of their Crimean venture as a bid to save the region from "Nazis"); and Crimea's population has just voted overwhelmingly in a referendum to join Russia. Yet those arguments, widely used to justify Russia's behaviour, tell only part of the story.

Yanukoych may have been legitimately elected but became hopelessly corrupt and serious questions remain about his use of force. The mob that finally ousted him did include far-right elements and this will cause significant concern among Ukraine's allies; nevertheless, they were in a minority and have yet to show signs of notable influence in Kiev. Sunday's referendum was not only illegal under Ukrainian and international law (and left no option for the status quo) but there is no way of knowing whether the electoral roll was properly compiled and how intimidated voters felt.

As for Russian claims to be a bulwark against intolerance, that will raise a bitter laugh among minority groups in Russia that have experienced first hand the discriminatory attitudes of the authorities and the Kremlin.

International acceptance of Crimea's annexation by Russia would be a dangerous precedent. There are very real concerns about Mr Putin's further ambitions, including that Moscow could send in forces to "protect" the Russian-speaking population in Donetsk and other parts of eastern Crimea. There are also concerns that Russia poses a renewed threat to other former Soviet states such as Latvia and Lithuania, while Lord Ashdown will warn in a speech today that the Russian president is meddling in Bosnia.

No-one wants war, except, perhaps, Mr Putin and some of his supporters. Targeted sanctions might help to prevent it and should be attempted.