In 1974, the war in I Corps erupted, the fighting led to the next big attack in the spring of 1975. This fighting heavily favored the north as the terrain would heavily favor the attackers. The region in which the fighting would take place was poor economically, but in spite of this, it was still of second greatest importance to the south, only behind Saigon. This was because of the attachment that Hue had to it, along with the deep-water harbor in Danang.
The North Vietnamese were previously held back from lack of roads, which kept them from creating favorable military advantages. However, the North Vietnamese had developed a road network out of the area they had captured in 1972. This would allow mass troops to form along with multiple supply stations in Corps I. The South Vietnamese would be at a disadvantage before the first shots were even fired. This, along with U.S. aid cuts greatly reducing firepower made for a deadly combination for the South Vietnamese army. In spite of an absence of sufficient ammunition of food and ammunition, the North Vietnamese continued their dominance of South Vietnam, as they grabbed loose South Vietnamese weapons and took food from the locals.
With the war looking grim for the South, President Thieu took action on March 25th to defend the remaining areas the South still had control of, no matter what the cost. He believed it was necessary to protect the coastal strip that existed from Binh Dinh province through Tuy Hoa down to Nha Trang. The recent dismantling of the groups on Route 7B made this task look extremely unlikely. The Communists would attack before Thieu had a chance to rebuild forces and morale.
On April 1st, the South Vietnamese were under a full-scale assault by the North Vietnamese. Despite a valiant effort by the South, on the morning of April 3rd the North captured Cam Ranh, and later that day would go on to capture the large military port at Cam Rahn. Instead of sending his soldiers to the next city in line, he immediately set his aims on Saigon.