The South Vietnamese had replaced the US army along the DMZ with a newly formed 3rd Division of untried and questionable quality. What was also new this time was a relatively massive use of tanks. They weren't perhaps the most useful vehicle in a country like Vietnam and the Americans tended to use the highly manouverable APC's or Armoured Personnel Carrier. These could be fixed up with all sorts of weapons, but basically had one 50 calibre heavy machine gun and two M60's. The US army did of course have tanks as did the South Vietnamese. With the American's having absolute control of the air their use by the communists was open to question. I think about four hundred were involved. I heard stories about their drivers being chained into position in the tanks. I had no way of verifying this. It might just have been propoganda.
The North were also mostly using regular troops from the North Vietnamese army now. The Viet Cong forces in the south had never really recovered from the massive losses of the offensive of 1968. If in the North there were relatively large reserves of men, in the South, for the Viet Cong, there were not. In the North everybody was used in the war effort. This was not the case with the government of Thieu.
A place called Camp Carroll was quickly overrun and then Quang Tri was attacked and also taken. I had a student who's father was, I think, the commanding officer at Camp Carroll. If I remember he went missing but showed up after the war having been a prisoner. She married the son of a cousin of KC. I also recollect the communists taking out a command post by firing a heat seeking missile at the air conditioning unit of the bunker concerned.
When I was in Van Kiep Quang Tri had been taken and briefly held one night by the Viet Cong. This must have been about 1966. It was taken again in the offensive of 1968, as was Hue. Now it had fallen once more. It was the most northerly town of any importance but its real strategic significance was that it opened the way to Hue which was now once again threatenened. Hue, the old Imperial Capital.