In the Vietnam War , how many Vietnamese civilians perished ?
The Centre for Public Policy Analysis and non-governmental organizations ( NGOs ) as well as Laotian and Hmong human rights organizations have provided evidence that since the end of the Vietnam War , significant numbers of Vietnamese military and security forces continue to be sent to Laos , on a repeated basis , to quell and suppress Laotian political and religious dissident and opposition groups including the peaceful 1999 Lao Students for Democracy protest in Vientiane in 1999 and the Hmong rebellion .