Australia was a key part of the Allied forces, and was one of the main reasons why the Allies won the war. The most important part that Australia played in World War II was on the Kokoda Trail. On the 23rd of July 1942, the Japanese advance party reached the Kumusi. The Australians engaged the advancing Japanese with ambushes, and made a stand on the 26th of July. One platoon remained at Kokoda. However, the Japanese managed to push back both platoons and took over Kokoda. However, when the Australian forces reassembled, they reoccupied the village unopposed on the 28th of July. This was when the first real battle happened, over the 28th and 29th of July. The Japanese managed to win this battle and forced the Australians to retreat to Denki.
On the 8th of August, an attack was made towards Kokoda, with three companies advancing on different lines. Two of the companies were forced to retire, but one company took hold of Kokoda. However, due to isolation by the Japanese troops they were forced to retreat on the 9th of August.
Many fights continued until the 11th of November, where the Australian forces took hold of Kokoda in a Japanese withdrawal of land. If Australia had not won this area, there would be a much thinner chance of winning the war.