1958 in the Vietnam War

After the communist states of Russia and China had betrayed Hanoi by allowing South Vietnam in December 1957, Hanoi began to look at an all military solution to the unification. Thousands of Viet Minh had stayed behind after the country had been split in two to help politically in the reunification election that never came. For years these southern cadres had been pressing to step the insurgency from low-level assassinations of South Vietnamese officials to full out military engagement with the South Vietnamese and their American allies. The American mission in South Vietnam Military Assistance Advisory Group (MAAG) was largest the only military aid mission anywhere in the world commanded by a lieutenant general, and the economic aid mission there was by 1958 the largest anywhere.

January
Armed insurgents attack plantations north of Saigon.

February
A South Vietnamese army truck is ambushed by insurgents and all occupants are killed.
 * February 12

March
As part of their efforts to advance the Unification referendum the North Vietnam via the Geneva machinery, forwarded messages to the Government of South Vietnam in July 1955, May and June 1956, March 1958, July 1959, and July 1960. These letters proposed loosening of economic restrictions between the two countries and preparations for a "free general elections by secret ballot,". Every time the messages were either rebuffed or ignored by the South Vietnamese government.

December
North Vietnam invades Laos near Huong Lap claiming that it was part of Vietnam not Laos. They later withdrew and had probably invaded to show their displeasure at the Laotian government moving away from their former neutral positions like recognizing Nationalist China.