The Afghan mujahideen were backed primarily by the United States, Saudi Arabia, Pakistan and the United Kingdom making it a Cold War proxy war. Out of the countries that supported the Mujahideen, the U.S. and Saudi Arabia offered the greatest financial support. However, private donors and religious charities throughout the Muslim world—particularly in the Persian Gulf—raised considerably more funds for the Afghan rebels than any foreign government; Jason Burke recounts that "as little as 25 per cent of the money for the Afghan jihad was actually supplied directly by states." Saudi Arabia was heavily involved in the war effort and matched the United States' contributions dollar-for-dollar in public funds. Saudi Arabia also gathered an enormous amount of money for the Afghan mujahideen in private donations that amounted to about $20 million per month at their peak.