When NVA tanks parked on the front lawn of South Vietnam's capital on 30 April 1975.
By force of arms.
By force of arms. The North Viet Army invaded the south and defeated it (or conquered it).
Which Vietnam? North or South?
Yes, some are still there.
Men of War: Vietnam Trailer
Battlefield: Bad Company 2 Vietnam TGS 2010 Trailer
Vietnam War: History and Key Dates
Visit Hanoi in Vietnam