An arms embargo against South Sudan failed to gain traction with the U.N. Security council Friday, delivering a blow to efforts to halt fighting in the young nation.The resolution, which also included targeted sanctions, fell two votes short of the mandatory nine needed for the body to adopt such measures. While, no permanent member of the council vetoed the proposed arms embargo, NPR's Michele Kelemen tells our newscast unit, prominent voices on the council, including Russia and Japan abstained from the vote."History is going to be a very harsh judge of their decision. The atrocities in South Sudan, the displacement to other countries is increasing every day," U.S. Ambassador Samantha Power told the council following the vote.Power, who introduced the resolution, said that while it was far from a "panacea," its passage would have brought consequences to what she called "the architects of mass atrocities and those who defy the demands of the Security Council day in, day out."Following news of the vote, several human rights organizations decried the resolution's defeat."South Sudanese civilians had a reasonable expectation that the Security Council would make good on its long-standing threat to impose an arms embargo and extend sanctions to some of the senior leaders who have been responsible for grave human rights abuses" said John Prendergast, founding director at the Enough Project, said in a statement circulated by Humans Rights Watch.The embargo's defeat follows worsening violence within the nation, which split from Sudan by popular vote in 2011. Shortly thereafter, fighting began between forces loyal to the President Salva Kiir and supporters of Riek Machar, the country's former vice president.As we reported earlier this month, the political conflict quickly cut across ethnic lines: