International migration has been steadily increasing in every region of the globe since the end of World War II. In recent times, individual mobility has increased enormously. Today, approximately 200 million people live outside the country where they were born, while tens of millions of people regularly cross borders. International mobility is part of a broader trend of globalisation, which includes trade in goods and services, investments and capital flows, greater ease of travel, and a veritable explosion of information. While trade and capital flows are often regarded as the twin pillars of globalisation, migration is often overlooked, especially among scholars of international relations. International migration is a key issue of our time. Large-scale international migration into Europe became a key issue across the region in the summer of 2015, when more than one million people arrived on Europe’s shores; most of them were fleeing political and/or economic turmoil. Specific issues included the multifaceted aftermath of the Arab Spring; continuing political, social, and economic ramifications of Syria’s civil war; declining state capacity in Iraq and Pakistan; state collapse in Afghanistan; and intra-Muslim sectarian violence across much of the Middle East. These individual factors coalesced in the context of globalisation and its effects upon national sovereignty. In Europe, right-wing populists are thriving on the divisions linked to these developments. In the USA, the Republican presidential candidate, Donald Trump, is building impressive electoral support. He claims that, as president, he would stop illegal migration from Mexico into the USA by building an impassable wall on America’s southern border, which he would compel ‘Mexico to pay for’. Today, political conditions in both Europe and the USA are reflective of many people’s approach to politics: they fear ‘uncontrolled migration’. This was manifested recently in the UK, where the vote to ‘Brexit’ from the European Union reflected a widespread belief that migration into the UK was ‘out of control’. Add to this the impact – and fear – of Islamist terrorism, and the result is an unprecedented ‘securitisation’ of international migration in Europe and the USA. This commentary focuses on the interactions between national sovereignty, globalisation, and the securitisation of international migration.