What was the most successful regimental campaign of the Vietnam conflict?

Operation Dewey Canyon is recognized as one of the most successful regimental campaigns during the Vietnam conflict due to its strategic impact and the execution of ground combat tactics. Conducted by the 9th Marine Regiment from January to March 1969, this operation aimed to disrupt North Vietnamese Army (NVA) logistics and operations in the A Shau Valley and the surrounding areas. The operation utilized a combination of infantry, artillery, and air support, leading to significant enemy casualties and a marked decline in NVA operations in the region after the campaign concluded.

The operation's success is reflected in its ability to achieve military objectives effectively while also boosting the morale of the U.S. and allied forces. The tactics employed during Dewey Canyon showcased the Marine Corps' ability to adapt to the unique and challenging environment of Vietnam, which contributed to its recognition as a successful campaign compared to other operations in the war.

In contrast, the other options pertain to various military operations that occurred but are not relevant to the Vietnam conflict. Operation Rolling Thunder was primarily an air campaign aimed at weakening North Vietnam's infrastructure and capacity to wage war, while Operation Enduring Freedom and Operation Desert Storm are related to conflicts in Afghanistan and Iraq, respectively, occurring much later than the Vietnam War