The Brooke government had been actively lobbying for the British government to accept Sarawak as one of its protectorates in an event of a war. By 1888, the British finally agreed to grant the protection to Sarawak. The British dispatched several troops to Sarawak to strengthen its defences in the 1930s. By 1938, under the leadership of Rajah Charles Vyner Brooke, airstrips were constructed in Miri, Kuching, Oya, and Mukah in preparation for an imminent war. However, by 1941, British Royal Navy and Royal Air Force had withdrawn from Sarawak and returned to Singapore. Therefore, the British government advocated a "scorched earth policy" for the Brooke government in the event of a Japanese attack. A Denial Scheme was formulated to destroy oil installations in Miri and Lutong. This was because the coastline measuring from Lutong to Miri was impossible to defend from Japanese landings due to shortage of manpower. By May 1941, 1 Infantry Company from 2/15 Punjab Regiment, 6-inch Hong Kong-Singapore Royal Artillery Battery, and 1 Platoon of Royal Engineers were stationed at Miri to oversee the destruction of the Miri oil fields. In August 1941, an operation was carried out to reduce Miri oil output by 70%.