President Obama has secretly sanctioned a huge increase in the number of US special forces carrying out search-and-destroy missions against al-Qaeda around the world, with American troops now operating in 75 countries.

The dramatic expansion in the use of special forces, which in their global span go far beyond the covert missions authorised by George W. Bush, reflects how aggressively the President is pursuing al-Qaeda behind his public rhetoric of global engagement and diplomacy.

When Mr Obama took office US special forces were operating in fewer than 60 countries. In the past 18 months he has ordered a big expansion in Yemen and the Horn of Africa — known areas of strong al-Qaeda activity — and elsewhere in the Middle East, central Asia and Africa.

According to The Washington Post, Mr Obama has also approved pre-emptive special forces strikes to disrupt terror plots, and has given the units powers and authority that was not granted by Mr Bush when he occupied the White House.

It also emerged yesterday that Robert Gates, the US Defence Secretary, has ordered the Pentagon to find savings of more than $100 billion (£68 billion) over the next five years to redistribute more funds for combat forces — including special operations units. Mr Gates has called on all departments to come up with proposals by July 31, and is initially demanding $7 billion in cuts and efficiencies for the 2012 fiscal year, and further cuts each year up to 2016.

The effort to provide more money for combat forces in Afghanistan and Iraq — including special operations units — is likely to lead to a clash with Congress, and also with the defence industry if favoured equipment programmes are scrapped.

The aggressive secret war against al-Qaeda and other radical groups has coincided with a surge in the number of US drone attacks in the lawless border region between Pakistan and Afghanistan, an al-Qaeda and Taleban haven, since Mr Obama took office.

Just weeks after he entered the White House, the number of missile strikes from the CIA-operated unmanned drones significantly increased, and the pattern has remained. In Iraq, US forces have killed 34 out of the top 42 al-Qaeda operatives in the past 90 days alone.

General Ray Odierno, the US commander in Baghdad, disclosed yesterday that special forces had penetrated the al-Qaeda headquarters in Mosul in northern Iraq, which had helped them to target key figures involved in financing and recruiting .

Mr Obama has asked for a 5.7 per cent increase in the Special Operations budget for the 2011 fiscal year — a total of $6.3 billion — on top of an additional $3.5 billion he requested this year.

Of about 13,000 US special forces deployed overseas, about 9,000 are evenly divided between Afghanistan and Pakistan. Their use, and the increase in drone attacks, is a strategy that has been strongly advocated by Joe Biden, the Vice-President, but criticised by the governments of Pakistan and Afghanistan. Hundreds of civilians have died in special operations A report last week revealed that the top US commander in the Middle East had signed an order last September authorising a big expansion of clandestine military missions in the region, and also in Iran, Saudi Arabia and Somalia.

General David Petraeus signed the Joint Unconventional Warfare Task Force Executive Order on September 30. In the three months that followed there was a surge of special operations troops into Yemen, where US operatives are now training local forces.

Since then, US military specialists working with Yemeni armed forces are said to have killed six out of 15 leaders of al-Qaeda in the Arabian Peninsula. The raids followed reports linking the group to the murder of 13 Americans at Fort Hood, Texas, and the attempted Christmas Day bombing of a Northwest Airlines jet.

The order also allowed for US special forces to enter Iran to gather intelligence for a possible future military strike if tensions over its alleged nuclear weapons programme escalate dramatically.

The seven-page document states that the surge is designed to build networks that could “penetrate, disrupt, defeat or destroy” al-Qaeda and other militant groups, and to “prepare the environment” for future military strikes by US and local forces.

• President Obama is reported to have chosen a US intelligence veteran, retired General James Clapper, as his new Director of National Intelligence. General Clapper, whose nomination comes at a time of mounting domestic terror threats, would replace Dennis Blair, who stepped down last month amid heavy criticism over a string of security lapses.

Under the radar

Nov 2002 Hellfire missile fired from a drone at a car in northwest Yemen kills six al-Qaeda fighters, including Qaed Salim Sinan al-Harethi, aide to Osama bin Laden and the planner of the bomb attack on USS Cole

Jan 2006 Missile attack on village of Damadola, Pakistan, kills 18 Pakistani villagers — but not the target, al-Qaeda’s No2, Ayman al-Zawahiri

June 2006 Abu Musab al-Zarqawi, al-Qaeda’s top man in Iraq, killed along with 18 others when a house near Baghdad is bombed by US jets

Dec 2008 Six members of the Afghan police force killed in exchange of friendly fire with US special forces near the city of Qalat

Sep 2009 Four helicopter gunships open fire on a convoy in Barawe, Somalia, killing four Islamic insurgents, including Saleh Ali Saleh Nabhan, linked to al-Qaeda

Source: Tim Reid and Michael Evans, Washington, Times archives