Jordan Duncan, 29, pleaded guilty in North Carolina in June to aiding in the manufacture of a firearm.

Duncan and four other men, including two other ex-Marines, were arrested in 2020 in connection with what authorities described as a neo-Nazi plot to sow chaos by targeting the power grid.

"We have now brought to justice all five of the defendants involved in a self-described 'modern day SS,' who conspired, prepared, and trained to attack America's power grid in the name of violent white supremacist ideology," Attorney General Merrick Garland said in a statement.

FBI Director Christopher Wray said the group was "inspired by racially motivated violent extremism."

"If the defendants had been able to carry out an attack it could have caused suffering to thousands of American citizens," Wray said.

The other four defendants were previously sentenced to prison terms between 21 months and 10 years.

According to court documents, two members of the group were active on "Iron March," a neo-Nazi online forum, until it was closed in 2017. They also recruited the other three people involved.

The group accumulated firearms and produced a video of live-fire training in the desert near Boise, Idaho, that ended with the phrase "Come home white man" as the final frame.

Components of the power grid in the northwestern United States were listed as potential targets in handwritten notes found in the possession of one of the conspirators.