A force of nearly 4,000 United States Marines landed on the island of Emirau on 20 March 1944. The island was not occupied by the Japanese and there was no fighting. It was developed into an airbase which formed the final link in the chain of bases surrounding Rabaul. The isolation of Rabaul permitted MacArthur to turn his attention westward and commence his drive along the north coast of New Guinea toward the Philippines. In February 1943, General MacArthur had presented the US Joint Chiefs of Staff with his Elkton Plan for an advance on the Japanese stronghold of Rabaul. In this "scheme of manoeuvre" the penultimate stage was the capture of Kavieng, an important staging post for aircraft moving from Truk to Rabaul. The Allied occupation of Kavieng would cut this route and isolate Rabaul. The Allied victory in the Admiralty Islands campaign in March 1944 prompted the Joint Chiefs of Staff to consider accelerating the tempo of operations in the Pacific. They solicited opinions on the matter from the theatre commanders. On 5 March 1944, armed with detailed information about Japanese deployments and intentions as a result of the capture of Japanese cryptographic materials in the Battle of Sio, MacArthur recommended omitting the proposed attack on Hansa Bay in favor of moving further up the coast of New Guinea to Hollandia. As this would be out of range of his land-based aircraft, he proposed that aircraft carriers of Admiral Chester W. Nimitz' United States Pacific Fleet, which were to cover the Manus and Kavieng operations could provide air cover until land-based aircraft could be established ashore. Admiral Nimitz, in Washington DC for consultation, objected to this proposal to retain forces in the South West Pacific theatre after the capture of Kavieng, as it would disrupt his plans for upcoming operations in the Pacific Ocean theatre. The Joint War Plans Committee discussed these alternatives, and recommended to the Joint Chiefs that Hollandia be seized on 15 April, but that the Kavieng operation be canceled. MacArthur's Chief of Staff, Lieutenant General Richard K. Sutherland, representing his commander before the Joint Chiefs, strenuously objected to the omission of Kavieng, which he believed could be captured on 1 April without delaying other operations. There was debate over how much of a threat the Japanese base at Kavieng was. Nimitz felt that as a result of the Battle of Eniwetok, Truk itself would soon be under constant attack and the flow of aircraft to Rabaul would be cut off. On 12 March, orders went out to MacArthur and Nimitz canceling Operation FOREARM [Kavieng] and ordering them to "complete the isolation of the Rabaul-Kavieng area with the minimum commitment of forces".