The Nato heads of government meet later this week in an important summit when they need to face up to their failure to maintain their core mission — the defence of the democracies of Europe and North America. Secretary General Anders Fogh Rasmussen’s proposal for a rapid deployment force is one part of a long overdue correction to the Nato member states’ delight in the savings offered by the peace dividend, which led them to fail to spot the renewed threat from Russia.

Russian President Vladimir Putin is well aware of Nato’s relaxed attitude and tested Nato’s political will when Russia took South Ossetia and Abkhazia from Georgia without any penalty in 2009, followed by Crimea earlier this year. Therefore, it was a shock for Russia to find that trying to destabilise east Ukraine was a red line for the pusillanimous Nato leaders, who finally realised that they had to support resistance to the Russians even by non-Nato members or face repeated Russian aggression and annexations.

But Nato has been ready to take on major missions outside its territory. In 2003, it went into Afghanistan with its Isaf allies and had been fighting there ever since. Some of the discussions in Wales will focus on how Nato can get out of Afghanistan by the end of this year with no effective government in that country to continue the stablisation that Nato has achieved. And now a new war is starting that Nato seems to want to be involved in. Its senior officials have been actively pondering how to support any efforts to defeat the Islamic State of Iraq and the Levant (Isil), which would require operations in Iraq and Syria, as has been speculated by General Martin Dempsey, chairman of the US Joint Chiefs of Staff. US President Barack Obama has said that America cannot accept the existence of the Isil ‘caliphate’ and he may well invite his fellow Nato members to join him in that view.

The danger is that Nato is becoming a roving global task force that follows the American lead into the most difficult and uncharted political territories. It would be better if the Nato leaders reminded Obama that the United Nations is where threats like this should be dealt with and let Nato stick to its core task of defending itself.