1942 was a year that presented the Australian government and Military with many hard decisions, and although Australia was already involved in the war, it was only now that the well being of our country was threatened by the possibility of a foreign invasion.
The leaders of Australias political parties and military force had realised that Australia was under threat of invasion. But, the Japanese had decided to put aside plans of an invasion and instead they would capture Port Moresby and the Southern Solomons and then take control of Fiji, Samoa and New Caledonia which would consequently, isolate Australia. Therefore the security of Australia would depend on the battle for Port Moresby, because if it were captured by the Japanese then they could strike at the north coast of Queensland whenever they were ready. Also if they captured Fiji then they could extend their air and naval bases which would then allow them to disrupt the lines of communication between Australia and the United States, which would make it extremely difficult for Australia to host a return attack against Japan.
Though capturing Port Moresby was not not as easy for Japan as they first thought and they were slowed down by three main battles;.
1. The Lexington and Yorktown raids against Japanese shipping in the New Guinea area in Febuary and March 1942- aircrafts Lexington and Yorktown which came fromUS Aircraft Carriers, attacked Japanese ships, which were landing troops at Lae and Salamana in New Guinea, sinking four vessels and damaging another seven that were supposed to support an invasion of Port Moresby. This delayed the invasion by one month.
2. The Battle of the Coral Sea in May 1942- where some land based aircraft from Townsville in Queensland, Australia, and the Lexington and Yorktown aircraft, struck at the force which were covering the Japanese invasion fleet. Lexington was lost and Yorktown damaged, but the invasion fleet was forced to turn back.