The spring of 1972 brought the largest North Vietnamese offensive of the war, and American strategy on the coast was straightforward: stand offshore and shell anything moving south along the coast highway toward the fighting in Quảng Trị. On 19 April four ships were working that stretch of the Gulf of Tonkin off Đồng Hới. USS Oklahoma City, a guided-missile cruiser, carried the Seventh Fleet flag. With her were the guided-missile frigate USS Sterett — a designation later changed, though the ship never was — and the destroyers USS Higbee and USS Lloyd Thomas. Naval gunfire support was routine, tedious, comparatively safe work. In seven years of war, no American warship off Vietnam had been attacked from the air. The crews had every reason to assume the pattern would hold.

Some forty-five kilometres inland, in Bố Trạch district, the Vietnam People's Air Force had built a strip called Khe Gát in seven months during 1969 and then made almost no use of it. It sat there for three years, an unremarkable line scraped into a valley. On the morning of 19 April two MiG-17Fs were waiting on it, flown by Lê Xuân Dị and Nguyễn Văn Bảy — the second of two well-known pilots of that name, distinguished in the records as Bảy 'B'. The MiG-17 was by 1972 an old aircraft, subsonic, short-legged, badly outclassed by anything the Americans put in the air. It was also small, and if flown low enough over broken ground, extremely hard to see coming.

Sterett's radar picked up three contacts inbound at about five in the afternoon. One MiG made two attack runs on Higbee and missed both times before coming round a third time and putting a BETAB-250 bomb into the destroyer's aft gun mount — the one the crew had just abandoned. The blast tore the turret apart, wrecked the steering and propulsion, and wounded four sailors working on deck. None of the crew was killed. The second MiG aimed at Oklahoma City and missed, leaving only superficial damage to her stern. Sterett fired Terrier surface-to-air missiles and claimed one MiG shot down, with a second contact vanishing from the screen alongside a missile, counted as a probable. The Vietnamese account is flatly different: two aircraft flew, two came home.

By six o'clock the task force was withdrawing to the northeast, and Sterett's operators found two surface contacts shadowing them. After half an hour of watching, she opened up with her five-inch gun and reported two North Vietnamese P-6 torpedo boats destroyed. North Vietnamese naval records show no boat engagement anywhere along that coast until 27 August. There was also a report, never confirmed in any official document, that a Styx anti-ship missile had been fired and intercepted. Radar at night in a crowded, jumpy tactical picture produces this sort of residue, and the honest summary of the evening is that the Americans knew what had hit Higbee and were considerably less certain about everything that followed.

The retaliation was immediate and heavy: bombardment of Vinh and Đồng Hới on 19 and 20 April, then a strike by thirty-three aircraft against Khe Gát on 22 April. The Americans claimed one MiG destroyed on the ground and another damaged; the Vietnamese recorded one damaged. Materially the raid had achieved very little — a wrecked gun mount and four wounded men. Symbolically it landed hard. This was the first air attack on American naval forces in the Vietnam War, and only the second time since 1945 that US warships had been bombed from the air, the earlier case being the attack on USS Liberty, officially recorded as a mistake. Daylight naval raids on the coast stopped. Ships that had operated in something close to routine now needed air cover, at a moment when the United States was trying to reduce its commitment rather than expand it. Khe Gát's runway is buried today under the Ho Chi Minh Highway.