Pre-war U.S. Involvement
Perpetually concerned about the spread of Communism, the United States increased support of South Vietnam the next month when President Dwight D. Eisenhower deployed the Military Assistance Advisory Group (later the Military Assistance Command, Vietnam or MACV). The role of the advisors was to provide strategic advice and military weaponry, as well as to train the Army of the Republic of Vietnam (ARVN). Although there is argument about the details of the United States' entry into this complicated military action, many recognize November 1, 1955, as the official entry point. The advisors faced a long and complicated task; in less than a decade, their numbers increased from only a few hundred to 23,000.
Wanting to overthrow Diem's government and reunite the country, North Vietnam began sending experienced Viet Minh troops southward to organize guerrilla resistance. Officially organized in 1960, these guerrilla fighters were called the National Liberation Front (NLF); however, the United States referred to them as the Viet Cong. The Viet Cong set up a successful supply network through Laos and Cambodia, called the Ho Chi Minh Trail, and began to recruit volunteers – whether official guerrillas, supporters, or coerced civilians. They appealed to the sense of nationalism within the population, replacing France with the United States as the country being framed as the imperialistic power, and they presented themselves as an alternative to the repressive reign of Diem. A Catholic man ruling a largely Buddhist population, Diem had proven to be a poor leader early on by raising taxes in poverty-stricken areas, replacing trusted local officials with his own appointees, and largely ignoring the general needs of the South Vietnamese.
As Viet Cong guerrillas infiltrated South Vietnam, American forces struggled to adapt to their methods of warfare; guerrilla groups often attacked and disappeared back into the jungle before units had a chance to respond. In many cases, the soldiers were unsure if a South Vietnamese peasant was a civilian or Viet Cong, often learning the truth only after a deadly attack. This mixing of enemy and civilian would eventually lead to many desperate situations.
In the 1962 Operation Ranch Hand, the United States began dropping chemical defoliants meant to destroy the food supply of the enemy and clear away their thick jungle covering. This would prove to be highly controversial in the following years, as many of these chemicals-Agent Orange being the best known-devastated the agricultural potential of the area and caused long-term health problems for both the Vietnamese and the American soldiers.
In the fall of 1963, the United States quietly supported a military coup to overthrow Diem. That November, Diem and his brother were arrested and executed by the South Vietnamese military led by General Duong Van Minh. Unfortunately, this only made the political situation worse and left South Vietnam close to total collapse.