David Remnick interviewed hundreds of people, including President Barack Obama for his new book The Bridge.
It charts the life and political rise of Obama up to his inauguration as president.
Mr Remnick says President Obama's aim to be a "conciliator" on the world stage has not worked out.
He says awarding him the Nobel Peace Prize in 2009 was "completely ridiculous" and he thinks Obama is learning now that the world is a much more stubborn place than he perhaps thought.
You can watch this HARDtalk interview on Monday 21 June on the BBC News Channel at 0430 and 2330 BST and on Monday 28 June on BBC World News at 0330, 0830, 1530 and 1930 GMT.