NEW YORK, May 22: Ahead of President Obama’s long-awaited address on drones at Washington’s National Defence University on Thursday, the New York Times said that drone strikes in Pakistan have fallen sharply since their peak in 2010, perhaps in response to increasing scrutiny of the programme by Congress and the American public.

President Obama embraced drone strikes in his first term, and the targeted killing of suspected terrorists has come to define his presidency.

However, writing about the declining drone strikes, Bruce Riedel, a former CIA analyst and Brookings Institution scholar, said in Foreign Policy magazine there were many reasons for the declining number of strikes in Pakistan.

“But a growing awareness of the cost of drone strikes in US-Pakistan relations is probably at the top of the list,” Mr. Riedel said. “They are deadly to any hope of reversing the downward slide in ties with the fastest growing nuclear weapons state in the world.”

But the Times pointed out lost in the contentious debate over the legality, morality and effectiveness of a novel weapon is the fact that the number of strikes has actually been in decline.

An administration official told NYT Mr Obama would also “review our detention policy and efforts to close the detention facility at Guantánamo Bay; and he will frame the future of our efforts against Al Qaeda, its affiliates and adherents.” Some supporters of Obama have urged him to use the occasion to announce that part of a 6,000-page Senate study of the CIA’s former interrogation programme will be declassified and made public.

Mr Obama, who insisted early in his presidency on a personal role in many strike decisions, may also shed light on the declining use of drone strikes. Current and former officials say the reasons include a shrinking list of important Al Qaeda targets, a result of the success of past strikes and transient factors ranging from bad weather to diplomatic strains. But more broadly, the decline may reflect a changing calculation of the long-term costs and benefits of targeted killings.

Obama administration officials have sometimes contrasted the drone programme’s relative precision, economy and safety for Americans with the huge costs in lives and money of the two wars in Iraq and Afghanistan.

Over time, however, the costs of the drone strikes themselves have become more evident.

Reports of innocent civilians killed by drones — whether real or, as American officials often assert, exaggerated — have shaken the claims of precise targeting. The strikes have become a staple of Al Qaeda propaganda, cited to support the notion that the United States is at war with Islam.

They have been described by convicted terrorists as a motivation for their crimes, including the failed attack on a Detroit-bound airliner in 2009 and the attempted car bombing of Times Square in 2010.