Thailand. (Laotian Civil War). 1971. Stamp-less envelope addressed to Bangkok, cancelled by Mongdon date stamp '13th Sept 1971' with 'Royal Thai Army Border Patrol Command' hand-stamp in carmine and Army Censor Checked cachet, signed by the Commanding Officer with Bangkok arrival.
Royal Thai Army Troops were stationed on the Thai/ Laos border as part of "Operation Phalat" a military offensive during the Laotian Civil War.