increasing troop levels
Timely troop movements, troop support, supplies, and strategic air stikes.
South Vietnam was our ally and the US did not want the communist N. Vietnam to conquer them. The whole Cold War era thing was wack!
One event that caused an escalation of troop involvement in Vietnam was the incident in 1964 at the Gulf of Tonkin.
During the Vietnam War, a US Army "Troop" was a US Cavalry "Company." Example(s): "A" Troop, "B" Troop, "C" Troop, etc. The Australian Army in Vietnam called their "Companies" a "Squadron", and called their "Platoons" a "Troop." (During the war) The US Army standard "Infantry" Platoon was approximately forty men. An "Armor" platoon (in Vietnam) consisted of 5 Patton tanks per platoon; with 20 tank crewmen per platoon...led by a 2nd or 1st Lieutenant.
US troop strength began to increase as the war in Vietnam continued without an end in sight. By the end of 1965, US President Johnson had authorized the 185,000 positioned in Vietnam.
Discounting US aircraft (fixed wing & rotor wing) the only troop transports used during the Vietnam war were US Navy vessels and the US Army's M113 APC/ACAV (Armored Personnel Carrier/Armored Cavalry Assault Vehicle).
The draft started before the US war in Vietnam. Your question is actually about when the USG started posting draftees to Vietnam. That would probably be in March 1966 when At Pres. Johnson announced a singificant build-up of US troop strength in March of that year. Prior to that, every announcement of further troop commitments included a statement that only volunteers were concerned.
they had the runs and were out of toilet paper