In justifying these arms shipments, the administration claimed that the regime had taken "positive steps" to investigate the murder of four American nuns, but this was disputed by US Ambassador, Robert E. White, who said that he could find no evidence the junta was "conducting a serious investigation." White was dismissed from the foreign service by the Reagan Administration after he had refused to participate in a coverup of the Salvadoran military's responsibility for the murders at the behest of Secretary of State Alexander Haig.Throughout the 1980 U.S. presidential campaign, Reagan and his foreign policy advisers faulted the Carter administration's perceived over-emphasis on the human rights abuses committed by "authoritarian" regimes allied to the U.S., labeling it a "double standard" when compared with Carter's treatment of communist-bloc regimes. Haig, who described himself as the "vicar" of U.S. foreign policy, believed the human rights violations of an American ally such as El Salvador should be given less attention than the ally's successes against American enemies, and thus found himself downplaying the nun killings before the House Foreign Affairs Committee in March 1981: