In 2004, declassified documents revealed that the U.S. was so distraught by the rise in oil prices and being challenged by under-developed countries that they briefly considered military action to forcibly seize Middle Eastern oilfields in late 1973. Although no explicit plan was mentioned, a conversation between U.S. Secretary of Defense James Schlesinger and British Ambassador to the United States Lord Cromer revealed Schlesinger had told him that "it was no longer obvious to him that the U.S. could not use force." British Prime Minister Edward Heath was so worried by this prospect that he ordered a British intelligence estimate of U.S. intentions, which concluded America "might consider it could not tolerate a situation in which the U.S. and its allies were at the mercy of a small group of unreasonable countries," and that they would prefer a rapid operation to seize oilfields in Saudi Arabia and Kuwait, and possibly Abu Dhabi in military action was decided upon. Although the Soviet response to such an act would likely not involve force, intelligence warned "the American occupation would need to last 10 years as the West developed alternative energy sources, and would result in the ‘total alienation’ of the Arabs and much of the rest of the Third World."