were to fight in an extraordinary variety of locations, including withstanding the advance of German Panzers in the Siege of Tobruk, turning back the advance of the Imperial Japanese Army in the New Guinea Campaign, undertaking bomber missions over Europe, engaging in naval battles in the Mediterranean. At home, Japanese attacks included mini-submarine raids on Sydney Harbour and very heavy air raids on and near the Northern Territory's capital, Darwin. The recruitment of a volunteer military force for service at home and abroad was announced, the 2nd Australian Imperial Force and a citizen militia organised for local defence. Troubled by Britain's failure to increase defences at Singapore, Menzies was cautious in committing troops to Europe. By the end of June 1940, France, Norway, Denmark and the Low Countries had fallen to Nazi Germany. Britain stood alone with its dominions. Menzies called for "all-out war", increasing federal powers and introducing conscription. Menzies' minority government came to rely on just two independents after the 1940 election. In January 1941, Menzies flew to Britain to discuss the weakness of Singapore's defences. Arriving in London during The Blitz, Menzies was invited into Winston Churchill's British War Cabinet for the duration of his visit. Returning to Australia, with the threat of Japan imminent and with the Australian army suffering badly in the Greek and Crete campaigns, Menzies re-approached the Labor Party to form a War Cabinet. Unable to secure their support, and with an unworkable parliamentary majority, Menzies resigned as prime minister. The Coalition held office for another month, before the independents switched allegiance and John Curtin was sworn in as prime minister. Eight weeks later, Japan attacked Pearl Harbor. From 1940 to 1941, Australian forces played prominent roles in the fighting in the Mediterranean theatre, including Operation Compass, the Siege of Tobruk, the Greek campaign, the Battle of Crete, the Syria–Lebanon Campaign and the Second Battle of El Alamein. A garrison of around 14,000 Australian soldiers, commanded by Lieutenant General Leslie Morshead was besieged in Tobruk, Libya, by the German-Italian army of General Erwin Rommel between April and August 1941. The Nazi propagandist Lord Haw Haw derided the defenders as 'rats', a term the soldiers adopted as an ironic compliment: "The Rats of Tobruk". Vital in the defence of Egypt and the Suez Canal, the siege saw the advance of the German army halted for the first time and provided a morale boost for