The Huế chemical attacks Attack occurred Presence on 3 June 1963 , when soldiers of the Army of the Republic of Vietnam ( ARVN ) poured Motion liquid chemicals from tear gas grenades onto the heads of praying Rite Buddhists in Huế , South Vietnam .

The findings exonerated Judgment_communication the ARVN soldiers from charges that they had used Using poison or mustard gas .

Both ARVN generals in the Mekong Delta , Le Van Hung and Nguyen Khoa Nam , committed suicide Killing after the surrender Surrendering .

The PAVN , under the command Control of General Văn Tiến Dũng , began Process_start their final Process_end attack Attack on Saigon on April 29 , 1975 , with the Army of the Republic of Vietnam ( ARVN ) forces Hostile_encounter commanded Control by General Nguyễn Văn Toàn suffering Bodily_harm a heavy artillery bombardment Attack .

The Army of the Republic of Vietnam ( ARVN ) expanded Expansion following a period of neglect after Tet , modeled on US doctrine .

After 1968 , Nixon 's policy of `` Vietnamization '' , saw Self_motion the conflict fought by an expanded ARVN with U.S. forces sidelined and increasingly demoralized by domestic opposition and reduced recruitment .

The ARVN , buttressed by said U.S. support , stopped Process_end the largest and first mechanized PAVN offensive to date during the Easter Offensive of 1972 , resulting in mutually heavy casualties , but failed Earnings_and_losses to recapture all territory , leaving its military situation difficult .

The three-year period of 1972 to 1974 saw heavy fighting and constituted the war 's bloodiest years for the ARVN .

The scale of fighting was enormous : by 1970 the ARVN was the world 's fourth largest army , with the PAVN being similar in size at around a million regular soldiers .