My daughter recently asked me what makes Australia worth fighting for. I started with the usual answers about freedom and democracy, but she wasn’t convinced. What she understood better were the things she could see and use: the power lines that keep our lights on, the wi-fi that lets her parents sometimes work from home, the networks that stream Bluey. Those visible threads point to a deeper truth: Australia’s strength rests not only on the security of our infrastructure but on the cohesion of our society. We are only as resilient as the cables that connect us to the world, and the bonds that connect us to each other.

Unfortunately, those threads are more fragile than many realise. In November, a single cargo ship severed critical undersea cables in the Baltic Sea. For hours, parts of Europe went digitally dark. Australia faces the same vulnerability. We depend on just 12 major cables for 99 percent of our international internet traffic. Cut enough of them, and we’re isolated faster than any naval blockade could achieve.

But this is about more than wires in the ocean. The same forces that threaten our cables also seek to erode the social bonds that make us a nation worth defending. The United States National Intelligence Council’s Global Trends report warned that democracies face growing risks from ‘the division of society into identity affiliations.’ When people retreat into silos, healthy patriotism withers and cohesion gives way to distrust and ugly nationalism. A country divided against itself cannot defend even the strongest infrastructure.

This is where digital security and social cohesion intersect. A nation that cannot protect its cables cannot credibly defend its sovereignty. But a nation too divided to protect its people cannot defend anything at all. This challenge is magnified when the Australian Defence Force is already struggling with recruitment, operating at around 4,300 personnel below its authorised strength. We cannot defend ourselves with what we cannot staff.

The fragility of our infrastructure and the fragmentation of our society were themes in my first speech to parliament, echoed since by many new members and senators of the 48th parliament. The answer is not retreat or division but clarity of purpose. We’re not just building stronger cables and data centres; we’re defending an open democracy where people from anywhere can come, contribute and belong.

Australia’s military tradition has always drawn strength from diversity. From Italian migrants who enlisted in both world wars, to second-generation Australians with surnames such as O’Brien, Komninos, Singh, Khoury, Chen, Nguyen and many more, our defence has always been collective. They chose to serve a country that had become theirs. Their shared purpose united us. It’s what inspired me, a boy born in Dublin, to lead a platoon in Afghanistan.

Yet we’ve largely abandoned the civic education that once made this story meaningful. Too many Australians no longer understand how democracy works, or why it requires active participation. When people don’t see their stake in Australia’s success, they become vulnerable to those who would divide us. And our adversaries know it. They probe our networks while targeting our unity, compromising both our systems and our will to respond.

Protecting our subsea cables therefore requires more than engineering fixes. Yes, we need multiple routes, onshore data centres and partnerships with allies. But these should be nation-building endeavours: new migrants working alongside established families, forging bonds as they lay the foundations of shared security. Australia’s history tells us when people build infrastructure together, they build commitment to defend it together.

The Global Trends Report sketched a ‘Renaissance of Democracies’ scenario, in which societies became more resilient through greater societal cohesion and civic education. That future is not guaranteed. It requires deliberate investment: national service programs that bring people together, civic education that reconnects citizens to our democratic story and infrastructure projects that are as much about community as they are about cables.

The economic stakes are immense. Each day, $22 trillion moves through subsea cables. A coordinated attack could devastate financial systems and take years to recover from. Every month we delay, our vulnerabilities grow, while adversaries grow bolder. The Baltic Sea sabotage revealed tomorrow’s warfare: infrastructure cut without warning, and months of disruption from minutes of sabotage. It also revealed tomorrow’s defence: nations recognising shared vulnerability and responding together. This is not a lesson exclusive to Europe, but rather a lesson that unites Europe and Australia.

Australia faces a choice. We can drift into digital isolation and social fragmentation, or we can strengthen the cables and communities that make us resilient. The Australian War Memorial reminds us that this has worked before. People from everywhere became Australians, then chose to defend what they had built together.

So, when any child asks what makes Australia worth fighting for, we should point to more than abstract ideals. We should point to the infrastructure we’ve secured together, the communities we’ve strengthened together and the story we continue to write together. The strongest threads are not only those lying on the ocean floor; they are the bonds between people who choose to call Australia home—people who choose to defend it, together.