I was in Abuja, the capital of Nigeria, when CNN announced that Obama had won. It was seven in the morning and, as word spread, the city seemed to surge with joy.

I could hear Obama's name shouted in the streets. People who spotted me as an American high-fived me and clapped me on the back. I’m told that many Nigerian babies were named Obama that day.

In Kano, a Muslim city in the far north of the country, a place where there are strong feelings against America, school kids chanted Obama’s name. In Rivers State, a poor area, a struggling health clinic posted a huge sign over its doorway that said ‘Yes We Can’. In Lagos, newspapers ran full-page ads congratulating Obama on his victory. From watching African and Middle Eastern television channels in my hotel, I could see the euphoria spread all over the developing world.

This outpouring was not just because a man of African descent was elected President of the United States. Something a lot deeper than that was going on.

In a way it reminded me of a time forty-five years ago when, hitchhiking around the world, I saw John Kennedy’s picture treated as an icon in mud huts and tinroofed shacks across the planet. But that was a kind of subdued reverence, a respect for a new leader who was young and handsome, and who seemed to care about the world and all the people in it.

This Obama feeling was more like a bolt of lightning, an arcing shock that in an instant made the impossible possible, and in whose light no challenge was beyond human reach, including, in the developing world, a seemingly endless list of ‘impossibles’ such as ending waterborne diseases and cleaning up the corruption that cripples progress. Two months before he takes the oath of office, Barack Obama instantaneously became a beacon of hope for countries whose own leaders do not provide that hope and, for most of them, never have.

I was in Nigeria speaking and leading workshops on citizen activism and community problem-solving. Suddenly the motivational part of my job got a lot easier. People understood the obstacles that Obama had surmounted and took heart that they could overcome the challenges they faced.

In meetings with political and business leaders, the talk turned to the practical lessons of Obama’s victory. His grassroots strategies and fundraising prowess could be learned and applied to Nigerian politics. One group I met with over lunch was already laying plans for a run at the Presidency by their favorite candidate, an accomplished woman who had, until then, seemed an impossible long-shot.

Nigerian attitudes toward the United States seemed to reverse overnight. Eight years of American foreign policy widely seen as bullying, selfish and shortsighted would now end. The stereotype of America as unalterably racist was smashed. Nigerians told me over and over that they want and need America to be a light of progress, and now that flame would be relit. America would be America again.

Of course, these expectations are impossibly high. There will be a letdown—but not a collapse, not if the new President stays true to the vision and principles on which he ran.

Above all, a President Obama must reverse the attitude and the tone with which America has dealt with the rest of the world for the last eight years. He must make it quickly clear that under his leadership American security will depend not just on resolute opposition to those who would do us harm, but on collaborative partnerships and a diplomacy of honest and respectful problem-solving. He must make it equally clear that American economic well-being will depend on trade and development policies that also build the prosperity of others, including the world’s poor.

My last day in Lagos I visited one of the most God-awful slums I have ever seen. Ragged kids there rushed up to touch my American hands. They shouted, ‘Hooray Obama’ and I shouted the same thing back to them.

We are all full of hope.

John Graham is the author of "Stick Your Neck Out; A Street-smart Guide to Creating Change in Your Community and Beyond" (San Francisco: Berrett-Koehler, 2005) and "Sit Down Young Stranger" (Langley: Packard Books, 2008). He is also President of the Giraffe Heroes Project www.giraffe.org and a former U.S. diplomat.