Theresa May, Britain's Prime Minister, ended 2016 by challenging her country to “seize an historic opportunity to forge a bold new role for ourselves in the world.” Since Britain is soon to trigger its departure from one of the largest and most powerful associations of nations, we would be wise to take her invitation seriously. It's time to put the gloom that many have felt about Brexit behind us. What, therefore, should be the UK's “bold new role”? Britain is already a supremely global nation. The UK is the fifth largest economy in the world (after the USA, China, Japan, and Germany). Our most important export/import partners include countries outside the European Union, including the USA and China. Britain's global political responsibilities are second only to the USA, being a member of the permanent five of the UN Security Council and an influential voice in the G7, G20, IMF, World Bank, NATO, and OECD. It's hard to imagine a country being more global than the UK already is. But being more global is our Prime Minister's call. Unfortunately, post-Brexit, the world's perception is that we are precisely the contrary. We are seen as a nation that is looking forward to a period of splendid isolation. As the New York Times recently noted, “Britain…has turned in on itself.” So what should we do? First, we should pause to diagnose our predicament. The USA is about to pursue an “America First” strategy. Europe is shrinking, quite literally—the UK represents 13% of the EU's total population. Multilateralism is fracturing. Terrorism is endemic. And since the 2008 financial crisis, public faith in government has collapsed. Still, there are good reasons to be optimistic. The Sustainable Development Goals have refreshed our vision of what the world might be. The Paris climate agreement was an unexpected success. The sovereign obligations of nations to peoples (a responsibility to protect among them) is now widely accepted. The world's leaders have never had more reliable evidence on which to base their decisions. And the demand for that evidence has never been greater. Here is a paradox. While global ambitions have been moderated, so grounds for a more confident outlook have strengthened. Second, we should define the UK's strengths. The government's understandable focus is on the economy—trade, industry, and financial services. But these strengths are only part of the reason for Britain's positive global reputation. Leaving aside our writers, musicians, and artists, whose international cultural footprint should place them at the forefront of post-Brexit strategies, Britain excels in four specific areas: science (and the academic research enterprise more broadly), health (the idea of universal health coverage, embodied in a national health service), higher education (the UK has 12 universities ranked in the world's top 100, second only to the USA), and development cooperation. Finally, those concerned about the UK's future should offer a clear prescription about what a new global role should be. Based on Britain's comparative advantages, it should be to enhance the lives and opportunities (including the economic opportunities) for people domestically and worldwide, with the understanding that these two geographic spheres of home and abroad are overlapping and inseparable. This objective is not altruistic. The more secure the lives of others, the more secure the lives of those living at home. Human security breeds human security. The UK should seek to increase its influence internationally with this goal clearly stated. It is likely that the realpolitik of Theresa's May's government will be to focus on hard power—Britain's ability to get what it wants by payment, threat, or coercion (exemplified today by dismal rhetoric regarding the country's terms of exit from the EU). But the UK's great strength lies in its soft power. Britain's aim must be to expand the currency of soft power—its supply of global public goods, the discovery, development, and delivery of benefits, especially knowledge, that are available to everyone, and which can be denied to no one. National self-interest post-Brexit depends on strengthening the institutions of knowledge creation, application, and dissemination at home, and connecting those same institutions with countries and peoples overseas. For those working in the medical sciences, our task is to make a convincing case for the expansion of one particular area of soft power—which means universities, health care, and development assistance. If such a vision could be realised, Brexit might indeed be a catalyst for remarkable new British contributions to planetary wellbeing.