By Matt Frei BBC News, Washington

President Bush defends the US's claim to the moral high ground Bush interview

The day was supposed to be all about Africa.

I was embedded in the presidential motorcade on the way to a speech in which President George W Bush would lay out the vision of his week-long trip to the continent.

But in Washington, political reality has a way of intervening in the best laid plans.

Even as Mr Bush was speaking at the Smithsonian Museum of African History, a flap with the Democratic-controlled Congress over his powers to combat terror burst into the open.

It was a subject we touched on after his address in a conversation in the library of the White House.

I asked whether his vow to veto a bill passed by the Senate which would outlaw water-boarding would not send the wrong signal around the world.

PRESIDENT BUSH'S ITINERARY Benin - Cotonou: arrival ceremony, meets president Tanzania - Dar-es-Salaam: meets president, tours hospital; Arusha: tours hospital, textile mill and girls' school Rwanda - Kigali: meets president, visits genocide memorial Ghana - Accra: meets president, state dinner Liberia - Monrovia: meets president, visits university Full interview transcript Bush interview: Your reaction Rice to visit Kenya

The president defended his position firmly, saying firstly that whatever the US did would be legal and secondly, that what he objected to was the imposition of a set of standards that the intelligence community thought would be ineffective.

"To the critics, I ask them this: when we, within the law, interrogate and get information that protects ourselves and possibly others in other nations to prevent attacks, which attack would they have hoped that we wouldn't have prevented?" he said.

"And so, the United States will act within the law. We'll make sure the professionals have the tools necessary to do their job within the law.

"Now, I recognise some say that these terrorists really aren't that big a threat to the United States any more. I fully disagree."

Running sore

The war against terror: with Mr Bush it always comes back to that key issue.

While we spoke, he was even considering delaying his trip to Africa in order to prevent the lapse of a law that allows the wire-tapping of terror suspects.

The situation illustrated the reality of a new kind of war versus the rhetoric of liberty.

It is the running sore of the Bush presidency, even in Africa: Darfur, a very topical case in point, which the president described again as genocide.

He insisted he was comfortable with his decision not to send in US forces to Darfur, but admitted he was "frustrated by the pace" of international action on the issue.

Asked whether the US still occupies the moral high ground after the Abu Ghraib prisoner abuse scandal and outcry over Guantanamo Bay, Mr Bush crisply and bluntly answered yes.

"We believe in human rights and human dignity. We believe in the human condition. We believe in freedom. And we're willing to take the lead."

The question is, with only 48 weeks left of his term in office, how many are willing to follow?