sentences:  The war had so far killed over 30,000 Americans and several hundred thousand Vietnamese citizens.By 1969, US public opinion had moved decisively to favoring ending the Vietnam War; a Gallup poll in May showed 56% of the public believed sending troops to Vietnam was a mistake.Of those over 50 years old, 61% expressed that belief, compared to 49% of those between ages 21 and 29, even if tacit abandonment of the SEATO Treaty was ultimately required and caused a complete Communist takeover of South Vietnam despite previous US guarantees.