WASHINGTON: Ever wish you could escape your troubles by changing your name and moving away? Well, according to President Barack Obama's top counterterrorism adviser at the White House, Osama bin Laden knew the feeling.

Hunkered down in his Abbottabad compound, bin Laden anguished as al-Qaida suffered "disaster after disaster," encouraged its operatives to flee to areas "away from aircraft photography and bombardment" and even thought about changing the name of his notorious international terrorist network, John Brennan said in a speech on Monday.

Brennan, Obama's Assistant for Homeland Security and Counterterrorism, told the World Wilson International Center for Scholars in Washington that bin Laden's pessimism was on full display in documents seized from his fortified home in the Pakistani garrison city. West Point's Combating Terrorism Center will display the papers this week.

Bin Laden worried about recruiting terrorist talent as U.S. strikes killed some of his veterans, fretting that "the rise of lower leaders who are not as experienced" would "lead to the repeat of mistakes," said Brennan.Al-Qaida's American-born public relations officer, Adam Gadahn, "admitted that they were now seen 'as a group that does not hesitate to take people's money by falsehood, detonating mosques [and] spilling the blood of scores of people,'" Brennan said in his prepared remarks.

Bin Laden himself "agreed that 'a large portion' of Muslims around the world 'have lost their trust' in al-Qaida," he continued.

"So damaged is al-Qaida's image that bin Laden even considered changing its name. And one of the reasons? As bin Laden said himself, U.S. officials 'have largely stopped using the phrase 'the war on terror' in the context of not wanting to provoke Muslims,'" said the U.S. official.

The core of Brennan's speech was a ringing defense of drone strikes at suspected terrorists, including American citizens abroad, which he called "legal, ethical and wise." Critics have called for greater judicial oversight of the process by which the U.S. government carries out targeted assassinations of Americans overseas.

And the United States reserves the right to pursue such attacks at any time and in any country in the world, he said. The attacks have drawn sharp criticisms from people in countries like Pakistan who regard them as outrageous violations of national sovereignty.

"As a matter of international law, the United States is in an armed conflict with al-Qaida, the Taliban and associated forces, in response to the 9/11 attacks, and we may also use force consistent with our inherent right of national self-defense," he said. "There is nothing in international law that bans the use of remotely piloted aircraft for this purpose or that prohibits us from using lethal force against our enemies outside of an active battlefield, at least when the country involved consents or is unable or unwilling to take action against the threat."

Brennan's remarks came as some Republicans ramped up criticisms of Obama's decision to use the raid that killed bin Laden as an argument for his own re-election. -- AGENCIES