One year on, Barack Obama’s election victory still feels like a momentous achievement. Yet it is dwarfed by what he is now striving to achieve in government. Already, his actions have had had far reaching consequences for America and the world.

Firstly, the Obama administration has brought stability to the US economy and set it on a course for future prosperity. A year ago, the United States was in the middle of the world’s greatest financial crisis since 1929. Since then, the stimulus package has helped to revive the economy and ploughed much needed investment into areas such as education and infrastructure. The administration’s tough stance on executive pay in those banks that have received government support has sent out a powerful message: that business leaders have a responsibility to society as well as to their shareholders, and that Wall Street must never again act with such disregard to the interests of Main Street.

Secondly, he has rehabilitated his country’s position on the international stage, and restored trust – not just of foreign leaders, but of billions of people around the globe – in the United States. In less than a year, he has brought a new approach to the Middle East, holding out an olive branch to all sides, and has been awarded the Nobel Peace prize. The step change in American foreign policy has built up a huge well of goodwill across the world. That will be vital in dealing with the situations he inherited in Iraq and Afghanistan, and also in addressing other threats to peace and stability, such as an unpredictable and volatile regime in Iran, and instability and insurgency in Pakistan. His powers of leadership and persuasion will be vital in securing a meaningful global deal on climate change at Copenhagen.

Thirdly, he has pressed ahead with ambitious policies that will serve the long-term interests of the United States. The most ambitious of these is his reform of healthcare, which promises to transform the lives of millions of Americans who currently have no health insurance. He has refused to be knocked off course by the frenzied reaction of those who oppose reform, and has sought to create a reform package that commands cross-party support.

He has been able to achieve this by harnessing the popular movement that helped propel him into the Whitehouse. Thirteen million Americans signed up to support Obama’s bid for the Presidency. Organising for America (OFA) is now using the same tools online and in the community to progress Obama’s agenda for change. Last month, OFA organised over 300,000 calls in a single day to members of Congress in support of healthcare reform. Many of those calls were generated through social networks as well as OFA emails. Across the United States, OFA volunteers have been knocking on doors and hitting the telephones to raise awareness of the plans and to get members of the public to lobby Congress in support of the reforms.

Sustaining that momentum is not easy. The idealism of a movement for change does not always sit easily with the political realities of achieving that programme in government. Yet the change that Obama and his administration are bringing to the United States and beyond will continue to serve as a beacon for progressives across the world.