US President George Bush has praised the out-going Pakistani president, Pervez Musharraf, as a key ally in the fight against Al Qaeda and other extremists. His comments came on the day Musharraf resigned from the post of Pakistani president. In a speech televised live to the nation, the former army chief defended his political record and said he had been made a scapegoat. Musharraf has been under pressure to quit since the coalition government said it planned to impeach him.