As a recent article puts the issue:
Though many of those neo-fascist fighters in Ukraine hearken back to popular figures in Ukrainian history who allied with the Nazis, few Americans and even fewer American policymakers typically cast a fond gaze at the ideology or history of the Third Reich. Thus, the dilemma: give up support for the neo-fascist militias and be seen as weak in standing up to Russia or support the militias and be seen as getting into bed with murderous neo-Nazis.
The first strategy of the Congress was to support all the militias, while hoping the press did not notice. This did not work out because the Associated Press and other media noticed that one of the militia groups being supported, the Azoz Battalion, actually uses an emblem from Nazi Germany.
Ukraine’s interior minister, Arsen Avakov,. said on his Facebook page that the Azov Battalion was one of the units to be trained by the US at a base in western Ukraine. The project will involve about 290 US paratroopers and about 900 Ukrainian guardsmen.
The Azov Battaliion is a volunteer militia that is part of the Ukrainian National Guard. The group has been quite effective in battle and has kept the city of Mariupol from being taken over by the rebels. It answers to the Ministry of Internal Affairs and has close connections with the the Ukrainian intelligence agency SBU. It turns over any prisoners it takes to the SBU and provides intelligence. The Daily Beast has an interview with a sergeant from the group, Ivan Kharkiv. He plays down the neo-Nazi links of the group. While the interview was taking place the paper reports this event:
As he speaks a young soldier walks over. Kharkiv introduces him. While shaking hands a large black tattoo becomes particularly visible on the young man’s extended upper bicep. The tattoo is an image of the Nazi eagle atop a black swastika.
The revelations that neo-Nazi groups or Nazi sympathizers were being funded led Congressmen John Conyers and Ted Yoho to submit an amendment to the House Defense Appropriations bill that would limit “arms, training, and other assistance to the neo-Nazi Ukrainian militia, the Azov.” The amendment passed in a unanimous vote in the US House of Representatives. However, in the final bill the amendment was gone. The Department of Defense successfully lobbied to have the ban removed.
The Pentagon claims the Conyers/Yoho amendment was not needed since legislation already exists — the Leahy law that would prevent the funding of Azov. However, the Leahy law only covers groups that the US Secretary of State has credible evidence of having committed a gross violation of human rights. This would be a much more limited ban than that envisioned by the Conyers/Yoho amendment. Since the U.S. was planning to train the Azov battalion in spite of the Leahy Law it should have been clear that the amendment was not redundant as claimed by the Pentagon. The Pentagon no doubt wants to fund the Battalion because it is one of the more effective forces against the rebels.
The government of Petro Poroshenko itself often faces problems with right-wing militias. It has even engaged in open conflict with the Right Sector militia.