Barack Obama, a leading Democrat candidate in the US presidential race, provoked anger yesterday by threatening to send troops into Pakistan to hunt down terrorists — even without permission from that country’s Government.

Standing in front of a Stars and Stripes flag, Mr Obama said: “There are terrorists holed up in those mountains who murdered 3,000 Americans. They are plotting to strike again . . . If we have actionable intelligence about high-value terrorist targets and President Musharraf won’t act, we will.”

The speech to the Woodrow Wilson Centre was designed to shore up his credentials as a potential commander-in-chief by backing a pre-emptive military action that even President Bush has so far refused to order.

Pakistan, a key ally of the US in the war on terrorism, reacted angrily, advising all American politicians to refrain from inflammatory remarks. “These are serious matters and should not be used for point-scoring,” Tasnim Aslam, a spokeswoman for the Pakistani Foreign Ministry, said. “Political candidates and commentators should show responsibility.”

Mr Obama’s outburst followed repeated clashes with Hillary Clinton, the front-runner for the Democratic presidential nomination in 2008, who in an opinion poll published yesterday leads Mr Obama 43 points to 22.

In a presidential debate last week Mr Obama said that he was willing to meet the anti-American leaders of Iran, Syria, Venezuela, Cuba and North Korea during his first year in office without any preconditions.

Mrs Clinton reacted by saying that she would not make any such promise because it might be exploited as a “propaganda tool”. She later described Mr Obama’s comments as irresponsible and naive.

Mr Obama hit back by describing her refusal to meet dictators as “Bush/Cheney-lite”, prompting another withering response from Mrs Clinton: “I’ve been called a lot of things in my life, but I’ve never been called George Bush or Dick Cheney.”

Much of Mr Obama’s speech yesterday appeared to be aimed directly at Mrs Clinton — without mentioning her by name. Mr Obama once again highlighted his opposition to the Iraq war in 2002 — when she voted to authorise military action — while also implicitly attacking her view that America was safer than it had been before September 11, 2001.

“Because of a war in Iraq that should never have been authorised and should never have been waged, we are now less safe than we were before 9/11. It is time to turn the page. It is time to write a new chapter in our response to 9/11,” he said.

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