On January 2, 1967, U.S. Air Force pilots executed one of the most audacious aerial deceptions of the Vietnam War. Designated as Operation Bolo, in less than half an hour more than half of North Vietnam’s Mig-21 force was knocked out of the skies. For months, American strike aircraft had suffered heavy losses due to North Vietnam’s expanding ground-based air defenses. In the skies, the North’s small and outdated air force was proving increasingly effective, using aggressive ambush tactics to disrupt strike packages before they could reach their targets. The arrival of state-of-the-art MiG-21 interceptors threatened to tip the balance even further against U.S. pilots. Operation Bolo was conceived by Colonel Robin Olds, a decorated combat veteran who recognized that regaining control of the skies would require outthinking the enemy. Since the start of the war, U.S. pilots had been constrained by strict rules of engagement drafted by administrators in Washington. Forbidden from striking