The unthinkable has happened. On 24th June, Britain voted to leave the European Union (EU) in a historic referendum. The results of the referendum have sent shock waves across the world, leaving many in disbelief and denial. It has thrown into question the fate of the EU and Britain that will no longer be the same. The implications of Britain’s exit have already begun to reshape the country’s future in profound and potentially disastrous ways. But what made this historic decision possible? The vote to leave the EU is a powerful symbol of a new era of globalisation and the rise of dangerous and divisive politics. We live in an increasingly uncertain and xenophobic world, the roots of which can be traced back to 9/11. The terror attacks of 9/11 unleashed a new era of fear, racism and paranoia. These emotions compounded in the wake of subsequent attacks on the European soil including the 7/7 bombings, and the recent terror events in Paris and Brussels, and the rise of extremist groups such as ISIS. The wars in the Middle East and the worst refugee crisis on record that has ensued as a result have given fresh boost to forces of racism and bigotry. The economic and security challenges facing the western world have profoundly transformed the social and political landscape. Xenophobia and bigotry have infected European and US political discourse. There has been a sharp rise in far-right popularity fed by growing cultural and economic insecurity. It is against this backdrop that the rise of Donald Trump and the Brexit movement can be understood. In the wake of the terror attacks in Paris and San Bernardino in late 2015, Trump quickly proposed a ban on Muslims entering the United States, a move that drew fierce criticism. However controversial Trump and his speeches may be, he is no illusion and presents a real threat. In France, the counterpart to Trump, Marine Le Pen has managed to gain significant political support. The recent mayoral campaign of London led by the Conservative candidate Zac Goldsmith was one of smear, racism and bigotry. Xenophobia or the fear of immigrants seems to be order of the day. We are witnessing extraordinary change manifested in the rise of anti-immigrant sentiment, giving way to exclusionary forces, which have the power to do the unthinkable. Brexit is a case in point. The motivations underlying the Leave campaign were not dissimilar to the sentiments that have fuelled the equally remarkable rise of Trump in America. At the heart of the Leave campaign was an unjust emphasis on immigration as the root cause of all the ills afflicting British society, exacerbated by failure of the EU to respond effectively. On the other hand, Trump had built his entire campaign on the idea that the country’s porous borders have not only threatened the rule of law but also changed the US in an unrecognisable way. His slogan “Make America Great Again” is deeply soaked in anti-immigrant sentiment, which implies that the United States is not good today because of the people we let in. Immigration has been a far more contentious issue in Britain. The history of British immigration is replete with controversial and often misleading campaigns aimed at driving net migration down. The Home Office’s “Go Home or Face Arrest” campaign of summer 2013, for instance, was charged with racism, and later banned for being misleading. Politicians in Britain have exploited the issue of immigration for political gains at the expense of creating fear in the British society. The resounding issue of immigration was unsurprisingly placed at the centrestage of Brexit debate. The Leave campaigners offered many reasons for rejecting the EU from Brussels being excessively bureaucratic to democratic deficit and excessive regulations. But the factor that was most heavily stressed was immigration. The Leave side promised supporters desperately-needed control over immigration. As a result, foreigners became the convenient scapegoat of the referendum campaign. The campaign exploited immigration to identify an enemy who could be blamed for fewer jobs, overburdened schools and the NHS and drop in public services. The government could never admit that these failures were not because of immigrants but because of its own neoliberal policies of austerity. Since confronting its own weaknesses was not an option, the government demonstrated smart political tactic by manipulating the powerful force of xenophobia to advance its agenda, and it sadly worked. It worked because the fear of immigrants and foreigners in western societies is at a record high in the wake of terrorism and economic stagnation. This is not to say that all those who voted Leave were driven by racism or xenophobia. But these forces were irresponsibly employed as political tactics to deflect attention from the core issues, and played a significant role in shaping the results. The vote to leave symbolises widespread fear, irrationality and distrust that is increasingly plaguing the US and Europe. A xenophobic revival, if not addressed, would continue to do immense harm and challenge the foundation stones of western society. More worryingly, it would potentially do immense service to militant groups like ISIS by fuelling division and alienation in communities, ingredients for radicalisation. We are in the midst of an extraordinary change regarding how people view themselves, their leaders and their communities. The Brexit vote and the rise of Trump are both manifestations of the change. There can be more, be warned! The writer is lecturer in International Development for University of London International Programmes