More than seven years after America declared war on the Taleban, Afghanistan still stands on the brink of disaster, President Obama declared yesterday as he unveiled a new regional strategy to win the war in South Asia. An additional 21,000 US troops will be sent to Afghanistan and civilian aid to neighbouring Pakistan will be trebled, Mr Obama said in a speech that showed his desire to take full US ownership of the deepening conflict.

He warned both governments that they had to take far greater responsibility in tackling their own corruption and the lethal insurgency that is threatening their survival.

Mr Obama spoke only hours after a suicide bomber demolished a mosque packed with hundreds of worshippers attending Friday prayers in the tribal region near the Afghan border, killing at least 50 people. It was the bloodiest attack in Pakistan this year.

The Khyber tribal region, where the bombing took place, is the main supply route for Nato forces in Afghanistan and has become a prime target for the Taleban. The militants have regularly attacked convoys. Pakistani security forces have started a campaign to clear the area of them and a senior Pakistani official said that the attack could be revenge for local support for the operation. An Afghan soldier later shot dead two US troops in northern Afghanistan.

“The situation is increasingly perilous,” Mr Obama said in Washington as the White House released its long-awaited review of US strategy towards Afghanistan and Pakistan. “It has been more than seven years since the Taleban was removed from power, yet war rages on, and insurgents control parts of Afghanistan and Pakistan.”

Mr Obama said that in nearly eight years since the September 11 attacks, al-Qaeda and it allies had moved to havens in the mountainous Pakistani side of the Afghan border, almost certainly including, he said, Osama bin Laden and his deputy Ayman al-Zawahiri. He called it “the most dangerous place in the world”.

He added: “Multiple intelligence estimates have warned that al-Qaeda is actively planning attacks on the US homeland from its safe haven in Pakistan. If the Afghan Government falls to the Taleban - or allows al-Qaeda to go unchallenged - that country will again be a base for terrorists who want to kill as many of our people as they possibly can.”

He said that other terror attacks, including the London 7/7 bombings, were tied to al-Qaeda in Pakistan, and that “the safety of people around the world is at stake”.

Mr Obama announced no grand vision of a democratic Afghanistan, or a timeline for withdrawal from a war that his advisers say will be long and hard. Instead, in a radical downgrade of the more lofty objectives set by President Bush, he said the mission was “to disrupt, dismantle and defeat” alQaeda in Pakistan and Afghanistan.

Yet one ambitious element of Mr Obama's plan is to recast the war as a regional conflict involving Pakistan, Russia, Iran, India, China and the Central Asian states. He said he wanted to forge a new “Contact Group” of all the nations to help to address the conflict.

One aspect of the plan not publicly addressed by Mr Obama is a decision to increase US drone attacks inside Pakistan, The Times has learnt. Mr Obama also hinted that military action could be taken by US forces inside Pakistan, with or without its approval. US intelligence officials believe elements in the Pakistani security forces have tipped off insurgents about impending US attacks and there is a reluctance to share intelligence.

Mr Obama's aides say that the President has now accepted that Nato allies will not contribute significantly more troops to the effort, although as The Times reported yesterday, the UK is to send an additional 2,000 British troops. The military aspect of the war will increasingly fall to US forces. At next week's Nato summit, Mr Obama will press allies for help in training Afghan forces.

In addition to 17,000 extra US troops that will be sent to Afghanistan, Mr Obama announced another 4,000 yesterday to help to train the Afghan Army and police. He is also sending hundreds of civilian experts to bolster reconstruction and tackle the opium trade, which provides the Taleban with billions of dollars each year.

Mr Obama is to ask Congress for $7.5 billion (£5.2 billion) in civilian aid over five years for Pakistan, to help it to build democracy and strengthen its infrastructure. The move is fraught with risk, given Pakistan's history of corruption.

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