The Significance of the Kokoda trail campaign in Australia's history because they was the first time anyone had ever defeated Japan. In WWII & if the Australian soldiers did not defeat the Japanese then they could have easily invaded & destroyed Australia, and also it was one of the hardest war that Australia has faced because there was about 625 Australians soldiers who were killed and over 1000 wounded. When Kokoda campaign started half of the Australians soldiers were in Europe fighting in the WW1 and at that time Australia was in crisis because we had few men to fight in Kokoda. If Australia lost this war Japanese could have invaded port moresby and then go onto destroy and takeover Australia, but the dedication and sacrifice from the men had been amazing which is why Australia won the battle ands if there hadn't of had been that much effort and support, Australia today would be completely different.