and essential war-related items such as food and oil. As the Allied air forces grew, they mounted an Oil campaign of World War II to deprive Germany of fuel. Neutral countries continue to trade with both sides. The Royal Navy could not stop land trade, so the allies made other effort to cut off sales to Germany of critical minerals such as tungsten, chromium, mercury and iron ore from Spain, Portugal, Turkey, Sweden and elsewhere. Germany wanted Spain to enter the war but they could not agree to terms. To keep Germany and Spain apart, Britain used a carrot-and-stick approach. Britain provided oil and closely monitored Spain's export trade. It outbid Germany for the wolfram, whose price soared, and by 1943, wolfram was Spain's biggest export-earner. Britain's cautious treatment of Spain brought conflict with the more aggressive American policy. In the Wolfram Crisis of 1944 Washington cut off oil supplies but then agreed with London's requests to resume oil shipments.James W. Cortada, "Spain and the second world war." Journal of Contemporary History 5.4 (1970): 65-75. Portugal feared a German-Spanish invasion, but when that became unlikely in 1944, it virtually joined the Allies. Cold War During the Malayan Emergency (1948–1960), the British military deployed herbicides and defoliants in the Malaysian countryside (including crop fields) in order to deprive Malayan National Liberation Army (MNLA) insurgents of cover, potential sources of food and to flush them out of the jungle. The herbicides and defoliants deployed by the British contained Trioxone, an ingredient which was also formed part of the chemical composition of the Agent Orange herbicide used by the U.S. military during the Vietnam War. Deployment of herbicides and defoliants served the dual purpose of thinning jungle trails to prevent ambushes and destroying crop fields in regions where the MNLA was active to deprive them of potential sources of food. Herbicides and defoliants were also sprayed from Royal Air Force (RAF) aircraft. On 17 November 1953, the Greek National Intelligence Service (KYP) proposed conducting tax audits on suspected communist book publishers and cinema owners, censoring Soviet movies and promoting Soviet films of particularly low quality. In 1959, KYP launched exhibitions of Soviet products in Volos, Thessaloniki and Piraeus. The bulk of the products were cheap and defective, purposefully selected to tarnish the Soviet Union's image. During the Vietnam War, between 1962 and 1971, the United States military sprayed nearly of various chemicals –