Complex sentence: Thomas L. Hughes, Hilman's successor, wrote in his review of McNamara's book that Whiting regularly briefed McNamara and Secretary of State Dean Rusk and warned Pentagon officials in August 1964 that North Vietnam would retaliate against American air bases after the bombings of Hanoi.
Split into simpler sentences: Thomas L. Hughes, Hilman's successor, wrote in his review of McNamara's book that Whiting regularly briefed McNamara and Secretary of State Dean Rusk. Whiting warned Pentagon officials in August 1964 that North Vietnam would retaliate against American air bases after the bombings of Hanoi.