Western powers cannot afford to ignore the annexation of Crimea. Photo: Reuters
No matter how hard Vladimir Putin tries to persuade us otherwise, there is no escaping the fact that the proposed annexation of Crimea by the Kremlin constitutes a blatant violation of territorial sovereignty that the Western powers cannot afford to ignore.
Moscow claims that 97 per cent of those who participated in the referendum voted to join Russia, and there is no doubt that its outcome was popular among local Russophiles. No sooner had the vote been counted than the Crimean parliament declared independence, and voted to change its clocks to Moscow time and adopt the rouble as its currency.
But if the referendum's outcome satisfies Crimea's pro-Russian majority, no one else should take its validity seriously. Indeed, territorial violations of this kind were the immediate cause of both world wars. More recently, the West has responded militarily against Saddam Hussein of Iraq and Slobodan Milosevic of Serbia to prevent them from bullying others.
No one in the West - for the moment, at least, is advocating similar intervention in Ukraine. But our leaders must establish the clear principle that unprovoked acts of aggression against defenceless neighbours will not be tolerated in modern Europe - or anywhere else, for that matter. Failure to do so would establish an unwelcome precedent for other states to pursue their irredentist ambitions, such as China occupying Taiwan, or Iran seizing Bahrain.
So in the wake of Mr Putin's land grab in Crimea, it is imperative that we now establish a grand strategy with the aim of intensifying Russia's international isolation. The medium- and long-term aim should be to ensure that the Russian leader and his clique of KGB hoods are no longer able to threaten the West and its allies - while avoiding a full-blown trade war that would, as this newspaper has warned, send the world economy into the deep freeze.
On Monday, the United States and European Union took the first tentative steps towards confronting Moscow by announcing travel bans and asset freezes against a number of Russian and Ukrainian officials - "politically significant" figures who have actively supported the Crimean putsch.
But if we really want to contain Mr Putin, then we should hit the Russians where it hurts most - the energy sector. Much is made of Europe's reliance on Russian gas, but in fact it is Mr Putin's economic survival that depends almost entirely on his ability to export his oil and gas reserves at premium rates. The latest estimates suggest that less than a quarter of the gas Europe uses, and as little as six per cent of its total energy mix, comes from Russia.
We do not need to close the pipelines tomorrow, nor could we. But most energy experts believe Europe is already paying over the odds for Russian gas. By restructuring the energy network to take in other producers, such as Qatar and Algeria, we could, within the space of just a few years, cut our dependence on Russia, with the disastrous implications that would have for Moscow's balance sheet.
The fact that Viktor Zubkov, the chairman of Gazprom, Russia's state-owned energy company, recently sold all his shares in the firm, shows what he thinks of Russia's long-term economic prospects. And this growing sense of isolation in Moscow would only deepen if the world's leading industrial powers followed through with their threat to expel Russia from G8.
For far too long, the West has kowtowed to Moscow in the hope of persuading Mr Putin to conduct himself according to international norms. That must now stop. No longer should British ministers visit Moscow and conveniently overlook vexing issues, such as the suspected involvement of its intelligence agents in the murder of Alexander Litvinenko. We must abandon the ludicrous policy initiated by Hillary Clinton as Secretary of State of "resetting" relations with Moscow.
Instead, America and its allies should redouble their efforts to construct an effective missile shield in central Europe to protect it against the threat of attack by rogue states. After Mr Putin's Crimean adventure, Russia - which has one of the world's largest nuclear arsenals - deserves to be treated as one of their number.
Nato must also raise its game dramatically. Rather than blithely announcing, as it did over Crimea, that it had no plans to intervene, it must make sure that its members give it the resources to respond effectively to future transgressions. Britain's offer of a squadron of Typhoon jets to join Nato's Baltic mission was a step in the right direction, but our militaries have been run down too far, and need to be built up.
All this will take time to accomplish, and will cause some short-term inconvenience. But a serious and sustained effort to isolate and neutralise Russia is the best and only way to deter Mr Putin from any further acts of territorial aggression.
The Daily Telegraph