No Free Navigation: Why the U.S. Navy Dropped 11,000 Mines Across North Vietnamese Ports 50 Years Ago

May 2022 marks 50 years since the United States initiated a campaign to cut North Vietnam off from international trade by sea through concerted attacks on its harbour network under Operation Pocket Money. The campaign began on May 9 when the U.S. Navy launched six A-7 Corsair and three A-6 Intruder attack aircraft from the carrier the USS Coral Sea which dropped 36 1,000lb naval mines at the port of Haiphong. The city represented a key hub of North Vietnamese trade, and 14 years prior had been largely levelled by French attacks to ‘teach the Vietnamese a lesson’ as part of a colonial war effort primarily funded by the United States. From May 9 to May 12 1972 following three days carrier based jets sowed 11,000 mines across North Vietnam’s ports and harbours which effectively brought maritime commerce to a halt. The operation represented the first use of naval mines against North Vietnam, and its initiation was preceded by a diversionary airstrike against the Nam Dinh railroad from the carrier USS Kitty Hawk and by a 30 minute naval bombardment of Haiphong’s air defences. 

U.S. President Richard Nixon announced the renewed assault on North Vietnam as follows: “All entrances to North Vietnamese ports will be mined to prevent access to these ports and North Vietnamese naval operations from these ports. 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. Rail and all communications will be cut off to the maximum extent possible. Air and naval strikes against North Vietnam will continue.” Although refraining from declaring war on North Vietnam, the Nixon administration oversaw further expansion of the American intervention in Vietnam’s civil war, While successfully undermining the northern economy, efforts to preserve a Western client state in South Vietnam ultimately proved futile with the country reunified and the south absorbed into the north within three years of the beginning of Operation Pocked Money.