On the face of it Gordon Brown’s speech on Afghanistan re-emphasised Britain’s commitment to securing stability in the country.

At a time when five British soldiers have been murdered by an Afghan policeman, the Prime Minister had a duty to tell the country that these lives had not been sacrificed in vain and that a stable, more democratic Afghanistan was not a pipedream.

However, Mr Brown has introduced a string of nuances that have raised the very doubts that he wished to dispel — notably that success is not guaranteed and that he is not prepared to allow soldiers to lose their lives on behalf of a government that fails to tackle corruption.

While this will serve as a warning to President Karzai to establish an administration dedicated to reform, Mr Brown has, in effect, linked the success of the military campaign to the integrity of the Afghan leader.

Although Mr Brown reiterated that Britain and its international partners cannot walk away from the mission in Afghanistan, the inference is that if Mr Karzai fails to meet the standards required of him, commitment from this country will start to waver.

“We will succeed or fail together and we will succeed,” he said. Introducing the possibility of failure, albeit tempered by a determination to succeed, weakens the military argument that, whatever happens, Britain, the US, the rest of Nato and international allies engaged in the campaign, cannot be defeated by the Taleban.

There is too much at stake. Defeat, or a perceived defeat, would encourage every other malign jihadist group to follow the Taleban route. The speech appears to be aimed more at President Karzai than giving comfort to the men and women of the Armed Forces and their families.

In his statement on October 14 Mr Brown never mentioned the banned word — failure. Instead, he emphasised steps being taken to improve the chances of winning and turning over the security of the country to the Afghans. It was mainly a positive statement.

Today, judging by the Prime Minister’s latest outpouring, the Government’s commitment is full of caveats and conditions. Lives lost in the future will be justified only if Mr Karzai sweeps away corruption and sacks his warlord allies. The murder of the five soldiers has made Mr Brown more pessimistic.

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