You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Pacific_War

Context:
President Franklin Roosevelt ordered General Douglas MacArthur in the Philippines to formulate a Pacific defence plan with Australia in March 1942. Curtin agreed to place Australian forces under the command of MacArthur who became Supreme Commander, South West Pacific. MacArthur moved his headquarters to Melbourne in March 1942 and American troops began massing in Australia. Enemy naval activity reached Sydney in late May 1942, when Japanese midget submarines launched a daring raid on Sydney Harbour. On 8 June 1942, two Japanese submarines briefly shelled Sydney's eastern suburbs and the city of Newcastle.

Question:
Who was the Supreme Commander of the South West Allied forces?

MacArthur