The U.S. was unwilling to suffer the humiliation of accelerating withdrawal as Quảng Trị Province began to collapse before the North Vietnamese Easter offensive.

Carrier air wing Commander Roger Sheets planned the mission with air wing mine warfare officer Lieutenant Commander Harvey Eikel, who was VA-22 operations officer, and United States Marine Corps Captain Charlie Carr, who would be bombardier-navigator in the lead plane establishing the critical attack azimuth and timing the mine releases.

[5] On 9 May 1972, a Lockheed EC-121 Warning Star made an early morning launch from Da Nang Air Base to support the operation.

[6] At daylight on the 9th, a destroyer force struck the Haiphong Harbor air defense batteries with a 30-minute bombardment from their 5-inch (127mm) guns, which preceded the aerial mining.

The strike force was commanded by Captain Robert Pace, who succeeded Admiral Robinson, and consisted of the USS Richard S. Edwards, Berkeley, Buchanan and Myles C. Fox.

[6] Chicago set general quarters at 08:40, and within minutes launched two Talos missiles at two MiGs in a holding pattern awaiting air control vectors on the approaching bombers.

United States forces have been directed to take appropriate measures within the international and claimed territorial waters of North Vietnam to interdict the delivery of supplies.

The U.S. Navy determined this was caused by magnetic radiation from a geomagnetic storm triggered by a coronal mass ejection on the Sun; this was confirmed by scientific research in 2018.

United States negotiators in Paris used an offer to remove the mines as a bargaining chip to encourage Hanoi to release prisoners of war.

USS Warrington was irreparably damaged when it detonated what was believed to be mislaid mines 20 miles (32 km) north of Đồng Hới on 17 July 1973.