Linebacker I differed from Rolling Thunder in that it:

• A. Used heavy bombers and had fewer restrictions than Rolling Thunder
• B. Was primarily a naval air campaign
• C. Focused on air superiority over the Gulf of Tonkin
• D. Targeted only military bases in North Vietnam

Answer: (A)

Linebacker I represents a shift to a more aggressive air campaign by using heavy bomber aircraft and relaxing many of the political and military restrictions that constrained Rolling Thunder. Rolling Thunder was a prolonged bombing effort meant to pressure North Vietnam but kept tight ROE and target limits, focusing on a more restrained, largely tactical strike outlook. In contrast, Linebacker I employed B-52s and other heavy bombers to hit a broader set of strategic targets—oil facilities, storage depots, rail yards, and other logistics hubs—with fewer restrictions, aiming to cut North Vietnam’s war-making ability more directly. So the defining difference is the move to heavy, sustained bombardment with looser constraints. It isn’t primarily a naval air campaign, nor limited to air superiority over the Gulf of Tonkin, nor limited to only military bases inland.