Ambassador to Vietnam Marc Knapper offers incense at the Road 9 National Martyrs' Cemetery in Quang Tri Province, Vietnam, January 11, 2022. Ambassador to Vietnam Marc Knapper (L) offers incense at the Road 9 National Martyrs' Cemetery in Quang Tri Province, Vietnam, January 11, 2022. Ambassador to Vietnam Marc Knapper offers incense at the Road 9 National Martyrs' Cemetery in Quang Tri Province, Vietnam, January 11, 2022. Ambassador to Vietnam Marc Knapper (L) offers incense at the Road 9 National Martyrs' Cemetery in Quang Tri Province, Vietnam, January 11, 2022. Ambassador to Vietnam Marc Knapper (R) offers incense at the Road 9 National Martyrs' Cemetery in Quang Tri Province, Vietnam, January 11, 2022.