“Donors in Saudi Arabia constitute the most significant source of funding to Sunni terrorist groups worldwide,” she said.
Three other Arab countries are listed as sources of militant money: Qatar, Kuwait and the United Arab Emirates.
The cables highlight an often ignored factor in the Pakistani and Afghan conflicts: that the violence is partly bankrolled by rich, conservative donors across the Arabian Sea whose governments do little to stop them.
The problem is particularly acute in Saudi Arabia, where militants soliciting funds slip into the country disguised as holy pilgrims, set up front companies to launder funds and receive money from government-sanctioned charities.
One cable details how the Pakistani militant outfit Lashkar-e-Taiba, which carried out the 2008 Mumbai attacks, used a Saudi-based front company to fund its activities in 2005.
Meanwhile officials with the LeT’s charity wing, Jamaat-ud-Dawa, travelled to Saudi Arabia seeking donations for new schools at vastly inflated costs – then siphoned off the excess money to fund militant operations.
Militants seeking donations often come during the hajj pilgrimage – “a major security loophole since pilgrims often travel with large amounts of cash and the Saudis cannot refuse them entry into Saudi Arabia”. Even a small donation can go far: LeT operates on a budget of just $5.25m (£3.25m) a year, according to American estimates.