The pessimism is overwhelming. During a series of meetings convened by a US foreign policy think tank last week (I am forbidden from naming the organisation), participants (whom I am barred from identifying) explored prospects for American engagement in global health. The opportunity is surely there for the taking. After 2 years in which a pandemic has gripped and ground down the world, America's superior resources, intellectual and material, should place the country in a prime position for leadership. But that was not the consensus among the foreign policy glitterati brought together in this mysteriously secret gathering. On the contrary, the mood was decidedly downcast. Gone, they concluded, was the romantic paradise of the George W Bush years. In its place came the dark times of Donald Trump. America entered a period of vicious nationalism. Diplomatic relations with allies frayed. The reputation of the most powerful nation in the world was shredded. Trump's legacy lives on in the more placid times of President Joe Biden. Domestic polarisation has reached record levels. American institutions have been browbeaten into passivity. Political commentators entertain the idea of American decline, even the ebbing of American democracy itself. Friends have lost trust in America's reliability. A disastrous US withdrawal from Afghanistan is Exhibit A in the case against US competency. Flourishing anti-science movements and an open contempt for public health are garlands around the neck of a dying nation. A contrast was drawn with the political climate post-9/11. Even at that moment of national crisis, Congress was able to mount a bipartisan investigation to learn lessons from a terrorist attack. The idea that politicians could join together to conduct a similar exercise in the aftermath of COVID-19 is a pipedream. American culture has regressed since 2019. The system is broken and there is little evidence that it can be repaired. Amid this internal anarchy, the notion that America could step forward to lead the world out of its pandemic-induced stupor is a fantasy. Viewed from a European perspective, these arguments from America's diplomatic and security cognoscenti are utterly specious. The Bush years were not an idyll to be looked back upon with affection. His regime manufactured new wars that continue to cast a shadow over the world. To American colleagues I would say that many of your European partners saw the election of President Biden as an example of your ability to reinvent your national purpose. We have welcomed a more collaborative and constructive vision from your leaders. And we seek opportunities to strengthen your resolve to revivify American leadership, including your leadership in science, medicine, and global health. An especially important moment comes later this year with your hosting of the seventh replenishment round for the Global Fund to Fight AIDS, Tuberculosis and Malaria. Your commitment to a redesigned Global Fund, whose mission is likely to be broadened to include pandemic preparedness and antimicrobial resistance, would inspire, support, and guide countries at a critical time of uncertainty. This is your moment to lead. Do not waste it. Those who travel in the slipstream of politics should recognise this moment for what it is—our best opportunity for a generation to project values of universality, equity, and inclusivity on those with political power. The pandemic provided a platform for scientists and health professionals to speak directly to the public, explaining the dangers of insidious infection, putting centre stage those in society who face particular vulnerabilities, and emphasising the importance of resilient health and education systems. We have built a strong bridge of trust between science and the public. The rebirth of the state as a means to protect people from economic hardship provides a firm foundation to remake the case for universal health care. We have a time-limited opportunity to shape the attitudes and practices of governments. In Democracy in America, Alexis de Tocqueville wrote about a world filled with people of great importance and extreme insignificance. Scientists and health workers have played important parts in limiting the adversities of the pandemic. But whether those contributions will one day be seen to have been significant remains an open question. For scientists and health workers in America and elsewhere, we must not allow this pandemic to announce an age of pessimism that defeats us twice over.