Since then, several unsafe and unprofessional incidents involving China’s navy and air force have been publicly acknowledged by the Australian government, from Chinese naval units using active sonar against Australian divers from HMAS Toowoomba in the Japanese exclusive economic zone in November 2023, to a Chinese fighter deploying flares in front of an Australian naval helicopter from HMAS Hobart conducting United Nations sanctions enforcement in the Yellow Sea in May 2023.

In total, six incidents have been publicly confirmed, though there are almost certainly more. This pattern of harassment toward Australian ships and aircraft operating to our north extends back more than a decade, something I have witnessed first-hand at sea. But both the nature and intensity of these encounters have escalated in recent years, and while the public may have become accustomed to hearing of them, we cannot lose sight of what they represent: deliberate actions in international airspace and waters that endanger the lives of Australian Defence Force women and men.

These incidents are also the canary in the coal mine for a rapidly changing security environment, driven by four prominent factors. First, the breakdown of the multilateral system that once helped dampen the use of military force by states. Second, the growing willingness of states to use force to settle disputes, from Europe and the Middle East to Asia. Third, the rapid expansion of China’s military capability. And finally, Beijing’s increasingly aggressive use of that capability, from coercive manoeuvres around Taiwan to dangerous incidents in the Philippines’ exclusive economic zone and beyond.

During my recent visit to Beijing for the Australia-China High Level Dialogue, Chinese officials were explicit: China views the South China Sea as part of its 'core interests' and believes that foreign military assets have no right to operate there, despite it being international airspace and waters under international law. Beijing feels justified in using increasingly reckless and dangerous behaviour to assert this claim; a stance that directly undermines the security of a maritime trade-dependent nation like Australia.

Trump confidently declared that while AUKUS served as a deterrent to China, 'we won’t need it'. When asked whether China would invade Taiwan, he replied that it would not, emphasising his 'good relationship' with Beijing.

But as Australia learnt on Sunday, the facts in the air over the South China Sea tell a different story. Warnings from Australia’s Defence Department are echoed even more strongly by senior leaders in the US Indo-Pacific Command, including Admiral Samuel Paparo, who earlier this year described China as being on a 'dangerous course,' noting that the PLA’s 'aggressive manoeuvres around Taiwan' in February were not 'exercises' but 'rehearsals'. His predecessor likewise warned that China’s strategy resembled a 'boiling frog', a gradual, deliberate escalation until it is too late to respond.

In this context, Trump’s ringing endorsement of AUKUS, and his personal commitment to sell nuclear-powered submarines to Australia, is significant. Sunday’s unsafe and unprofessional incident by the PLA is yet another clear example of a deteriorating regional environment in which Australia’s national security interests are directly challenged.

While conflict is not inevitable, I don’t share Trump’s rosy outlook on China. Australia must prepare for the possibility of crisis or conflict; not to invite it, but to deter it. And if deterrence fails, we must be ready to respond. Australia cannot afford to become the desensitised boiling frog.