Garegin or Karekin Pastermadjian ( classical ) , better known by his '' nom de guerre '' Armen Garo or Armen Karo ( Արմէն Գարօ ; 9 February 1872 &ndash; 23 March 1923 ) was an Armenian nationalist activist and politician . Armen Karo was a leading member of the Armenian Revolutionary Federation for more than two decades . He was one of the masterminds of the 1896 occupation of the Ottoman Bank in response to the Hamidian massacres and Operation Nemesis , in which several perpetrators of the Armenian Genocide were assassinated . Between 1918 and 1920 he served as the first ambassador to the United States from the First Republic of Armenia
Hamidian massacres
Hamidian massacres
Armen Garo