Osama bin Laden was plotting to relaunch al-Qaeda´s campaign of terror on America with a "new phase" of jihad, including a 9/11-style spectacular and the assassination of President Barack Obama, documents seized from his hide-out show.

Frustrated by a series of setbacks and a western world distracted by the economic crisis, the al-Qaeda chief wanted a sharply honed comeback, which is detailed across 175 pages of plans and memos sent between the top echelons of his terrorist network and released by the US yesterday.

To bring down the infidel "tree", bin Laden wanted disciples to "focus our saw on its American root", ignoring even its "British branch" to avoid wasting limited resources. He also called on lieutenants to abandon plans for moves into Iran and possibly scale back operations in Pakistan and Yemen.

"I plan to release a statement that we are starting a new phase to correct the mistakes we made," he said in a 2010 memo. "We shall reclaim, God willing, the trust of a large segment of those who lost their trust in the jihadis." He lamented the PR disaster of killing Muslim civilians.

Bin Laden, who was killed by US forces in a raid on his compound in Pakistan in May last year, had delegated plans for "a large operation in the US" by up to ten suicide bombers plucked from Gulf states to Atiyah al-Rahman, one of his senior commanders. Rahman was eventually also killed last year.

He also wanted to kill Mr Obama as the US president travelled in a plane. Bin Laden argued that the assassination would see an "utterly unprepared" Vice President Joe Biden elevated to the Oval Office and plunge the US into crisis. He also wanted jihadis to kill Gen David Petraeus, the then-commander of US forces in Afghanistan and "man of the moment".

An exhaustive memo from Bin Laden´s American-born spin doctor, Adam Gadahn, disclosed detailed plans for rebranding the network and reinvigorating its supporters by capitalising on the tenth anniversary of the September 11 with a publicity blitz in western media.

Bin Laden or his deputy Ayman al-Zawahiri were considering granting television interviews, while reporters – including two in Britain – were set to be handpicked for exclusive anniversary material that might put the threat of global jihad back in the headlines.

"All the political talk in America is about the economy, forgetting or ignoring the war and its role in weakening the economy," wrote Gadahn, who said the group might even need to rename itself to seize back the initiative.

Plans for ambitious new fronts were floated by several of bin Laden´s lieutenants, including one to persuade Irish Catholics who were disenchanted with the church due to sex abuse scandals to turn to Islam rather than secularism.

However bin Laden remained focused on the nation he labelled the "head of the infidels". "If God wills it, America´s head can be cut off," he wrote. "Once the head has been removed, then it would be easier to cut off America´s wings".

Yet the documents depict him as a chairman struggling to maintain control of a sprawling and chaotic board. In memos fired off from his Abbottabad compound he repeatedly attempted to discipline regional commanders who he believed had ideas above their station.

The Yemeni-based al-Qaeda in the Arabian Peninsula were ordered to rein in plans to target their domestic government and declare an Islamic state. Tehrik-e-Taleban, the Pakistani offshoot, were condemned for indiscriminately attacking Muslims and an excessive use of kidnap. Meanwhile al-Shabab, the hardline Somali jihadists, were rebuffed after asking for a formal merger.

One document may even point to a split right at the top of al-Qaeda, according to the US Army´s Combating Terrorism Centre, which released the documents. A letter to bin Laden from a senior colleague, "possibly" Zawahiri, urged him to reconsider his rejection of the Somali alliance. The merger eventually went ahead after bin Laden was killed and Zawahiri took charge. (© Copyright of Telegraph Media Group Limited 2012. 05/04/12)