Twenty-five years after 9/11, divisions over Islam, identity and conflict remain powerful, raising an enduring question about how diverse societies can live together without turning cultural difference into fear and hatred.

Twenty-five years after the terrorist attacks of 11 September 2001, our world is experiencing terror, violence, atrocity and hatred. Nearly 3,000 people were killed when al-Qaeda hijackers attacked the World Trade Center and the Pentagon, while the courage of passengers prevented a fourth hijacked plane from reaching its target.

The attacks transformed US foreign policy and national security and helped set in motion wars in Afghanistan and Iraq whose human consequences extended far beyond the original violence. The legacy of 9/11 changed the way many societies imagined the relationship between Islam and the West, between ‘us’ and ’them’, and between cultural difference and political danger. That is why, 25 years later, we should ask two questions: how did 9/11 happen, and what did it teach us about living together?

In the aftermath of the attacks, George W Bush declared that the world had to choose between being ‘with us’ and the terrorists. The statement expressed the determination of a nation that had just suffered an extraordinary attack. But the political atmosphere that followed also encouraged a dangerous simplification: the idea that the world could be divided into opposing camps.

The binary ‘us/them’ mentioned by George W Bush had intellectual precedents. Samuel Huntington’s influential ‘clash of civilisations’ thesis had proposed that future conflicts would increasingly occur along cultural and civilisational fault lines. Francis Fukuyama, in a very different argument, had predicted liberal democracy as the endpoint of ideological struggle. The continuing debate between these visions is significant because it shapes how we interpret conflict: do we see people primarily as members of competing civilisations, or as individuals whose identities and political interests are more complicated?

Twenty-five years after 9/11, Huntington’s ideas still shape how we see global conflict. As Nils Gilman recently observed in Foreign Policy, the contemporary world has given renewed attention to Huntington’s emphasis on cultural and civilisational identity, even if the reality of global conflict has proved more complicated than his original thesis suggested. Civilisational thinking can be both historically inaccurate and politically dangerous, because when we begin to understand people primarily through civilisational categories, individuals disappear behind collective identities and undergo a process of symbolic becoming: a Muslim becomes an embodiment of Islam, an American becomes a symbol of the West, a refugee becomes a security question, and a believer becomes a potential fundamentalist.

The history of 9/11 also reminds us that the response to an atrocity can shape its consequences. The attacks were an act of extraordinary violence. Nothing should diminish the responsibility of those who planned and carried them out. But acknowledging that responsibility does not mean that every subsequent response was inevitable or beyond criticism.

As Greg Barton has argued in The Conversation, one of the great dangers following terrorism is failing to recognise how the response to outrage can amplify the original violence. The wars that followed, the enormous human and financial costs, and the transformation of global security politics demonstrate that the consequences of an atrocity can extend for decades.

There was also a social consequence. In the years following 9/11, Muslims and people perceived to be Muslim in Western societies increasingly found themselves navigating suspicion, stereotyping and the assumption that their cultural or religious identity needed to be explained or defended. The danger was that the actions of a small group of extremists could become attached, however implicitly, to millions of ordinary people, and that is precisely the kind of moral shortcut that a democratic society must resist.

For Australia, this question is particularly important because multiculturalism is not an abstract ideal, but an essential part of our everyday social reality. According to the Australian Bureau of Statistics, more than a quarter of Australians were born overseas at the 2021 Census, while more than half of Australians had either been born overseas or had at least one parent born overseas. More than five million Australians reported speaking a language other than English at home. Australia is not a culturally homogeneous society that has only recently begun encountering difference; diversity is already part of who we are. We encounter it in our schools, workplaces, universities, neighbourhoods, sporting clubs, religious communities and public institutions.

The question is whether we can turn this diversity into more than demographic coexistence. Multiculturalism is not simply that different groups live alongside one another while remaining socially separate, or that people must abandon their histories, beliefs or cultural identities in order to become Australian. The more demanding objective of multiculturalism is shared civic life. People can retain different identities while recognising a common obligation to one another. They can disagree profoundly about religion, politics, foreign policy or social values while still accepting that their neighbours possess the same dignity and rights.

The Scanlon Foundation Research Institute’s 2025 Mapping Social Cohesion report found that Australia’s overall level of social cohesion remained stable, although prejudice and discrimination towards some immigrant and faith groups remain persistent. Australians broadly support the idea of a multicultural society, but multiculturalism requires continual work if it is to become a lived ethical practice rather than simply a national slogan. Diversity does not guarantee social cohesion; cohesion has to be created and protected.

This is where the idea of passion becomes important. Coexistence is sometimes misunderstood as asking people to become less committed to their beliefs, but a society without conviction would not necessarily be a more ethical society. We need passionate people who care deeply about justice, freedom, dignity, equality, community and human life.

But passion can become destructive when it depends upon hatred. We can passionately oppose terrorism without hating Muslims, and criticise Western foreign policy without justifying terrorist violence. We can defend religious freedom without demanding that everyone share the same beliefs, and love our own culture without regarding another culture as a threat. This requires disciplining passion ethically, particularly in a democratic society, where we must recognise one another as legitimate participants in a shared political community despite disagreement. Tolerance is sometimes presented as simply putting up with people who are different from us. Coexistence demands more. It asks us to recognise that our lives are interconnected and that our freedom carries responsibilities towards others.

Twenty-five years after 9/11, the world remains marked by war, displacement, ethno-religious hatred and political violence. The temptation to divide humanity into opposing camps remains powerful. But Australia gives us another possibility.

We arrived in Australia about two years ago, and we found it a welcoming country. What I have learnt in this short time is that our multicultural society is an imperfect experiment in living with difference. Its success does not depend upon eliminating cultural, religious or political disagreement. It depends upon whether we can transform difference from a source of fear into an ordinary feature of shared civic life. We need the passion to resist injustice, the courage to confront violence, and the imagination to see beyond the categories that divide us.

Coexistence is not the absence of disagreement; it is the decision to live with disagreement without turning the other person into an enemy. Perhaps, after 25 years, this is one of the most important things we can learn from 9/11: that the opposite of hatred is not indifference, but an ethical commitment to living together. An ethical life begins when we stop seeing the others as strangers and recognise them as human beings.

The views expressed in this article may or may not reflect those of Pearls and Irritations.