“The idea in the jihadist forums is that McCain would be a faithful ‘son of Bush’ — someone they see as a jingoist and a war hawk,” Raisman said. “They think that, to succeed in a war of attrition, they need a leader in Washington like McCain.”

Islamic militants have generally had less to say about Obama. Leaders of the Iranian-backed group Hezbollah expressed a favourable view of Obama during the primary campaign but later rejected the Democrat after he delivered speeches expressing support for Israel.

In an e-mail response, senior McCain foreign policy adviser Randy Scheunemann noted that al-Qaeda leaders have repeatedly said that America “did not have the stomach to fight them over the long haul”, which the Arizona senator has pledged to do. “Whatever musings and bravado on radical websites the Washington Post chooses to quote, the fact remains that only John McCain has the experience, judgment and fortitude to lead a country at war,” he said. The Obama campaign declined to comment on the Web postings. Both the Bush administration and the two major presidential campaigns have rejected any suggestion that the economic downturn will undermine the country’s fight against the al-Qaeda.

From shortly after the September 11, 2001, al-Qaeda attacks to last year, US defence spending rose from 3 to 4 per cent of gross domestic product, but it remains far below the 45-year average of 5.5 per cent. The Pentagon’s budget for fiscal 2009 is $527 billion, a figure that does not include Iraq and Afghanistan war costs, which have totaled more than $800 billion since 2001.