[1]: 149 The Division was the target of Operation Mouette, launched on 15 October 1953, with the aim "to fix and destroy a major element of the Chu Luc before Giáp could deploy it.

"[1]: 221  The route for the Viet Minh between Thanh Hoa and the Red River Delta contained a crossroads at Lai Cac which was targeted by the operation.

Seven Mobile Groups (Groupes Mobiles) were deployed with river and amphibious units; tank units (largely the M24 Chaffee); half-tracks and paratroopers at designated landing sites, after counter-intelligence misled the Viet Minh into defending the wrong locations.

[1]: 222  The French claimed over 1,000 Viet Minh killed and 2,500 wounded, while 182 were captured, along with "500 infantry weapons, plus 100 bazookas and recoilless guns and 3,000 mines.

[1]: 239 In late December 1953 General Giáp ordered the Division to infiltrate into the Red River Delta and assist Viet Minh local regiments to increase the pressure on the French in this region while he concentrated his forces for the Battle of Dien Bien Phu.

On 9 April the 1st Battalion, 5th Cavalry Regiment was ambushed by a division unit resulting in 16 U.S. dead for the loss of 80 PAVN.

On 10 April a night attack north of Nhi Ha was broken up by air, artillery and naval support, 159 PAVN were killed.

[3]: 309–10 On 12 August 1968, a deserter from the 64th Regiment revealed that the Division had once again crossed the DMZ and was moving to positions near Cam Lo.

In response to this the 3rd Marines deployed north of the Cam Lo River on 13 August and engaged the 8th Battalion of the 64th Regiment, killing 43.

By 19 March the Division's 64th Regiment was operating east of Ban Dong/A Luoi (16°38′06″N 106°25′48″E / 16.635°N 106.430°E / 16.635; 106.430) in an attempt to prevent ARVN withdrawal along Route 9.

The Division then proceeded down Highway 7 into Phú Yên Province, capturing Tuy Hòa on 1 April.