In his speech, President Barack Obama is telling the audience that "in a world of new threats and new challenges," they should choose "leadership that has been tested and proven."
He didn't feel that way four years ago.
His campaign in 2008 was built on the ideas of hope and change. And during that time, he hit back against the idea that national security experience was critical for a new president. At the same time, opponent John McCain's camp was criticizing him for having very little experience governing.
Nor was the issue a small one four years ago. Polls indicated back then that many voters perceived Obama's biggest weakness then as his lack of foreign policy and national security experience, especially at a time when America was embroiled in wars.
Since then, of course, Obama has gained much experience during four years as president. Now, he says, experience is important.
EDITOR'S NOTE — Convention Watch shows you the 2012 political conventions through the eyes of Associated Press journalists. Follow them on Twitter where available with the handles listed after each item.