Steve Coll, whose résumé as a journalist includes two Pulitzer Prizes, a stint as managing editor of The Washington Post and a job as a staff writer at The New Yorker, is now ready to try his hand at something else: a Washington public policy institute. Mr. Coll plans to take over a nonpartisan public policy institute, the New America Foundation, in September…. After winning a Pulitzer Prize in 2005 for “Ghost Wars: The Secret History of the CIA, Afghanistan, and bin Laden, From the Soviet Invasion to September 10, 2001,” he left the paper to write for The New Yorker, which he will continue to do. This new position, he said, will permit him to “preserve a little bit of my own life as author” and to collaborate with a group of “smart engaged people who are part of a conversation that I want to be a part of.”