The book criticizes Kerry's judgment in battle, his truthfulness, his entitlement to certain medals, and his later anti-war activities. The book was based in part on interviews with veterans who served in or with Kerry's division, and also on biographies of Kerry. Several members of Kerry's crew stated that O'Neill failed to interview them. Neither O'Neill nor Corsi had any firsthand knowledge of Kerry's service. O'Neill served on the Swift boats after Kerry left Vietnam and Corsi never served in Vietnam. According to the Swiftboat skipper who served with Kerry, the book was "wrong."