Joshua Bowles, 29, repeatedly stabbed the unnamed woman, who was working at British intelligence agency Government Communications Headquarters (GCHQ), in March near its base at Cheltenham, England.

Following his arrest, Bowles told the police, “The target was selected for employment at the NSA.”

“Due to the size and resourcing, American intelligence represents the largest contributor within the intelligence community, so made sense as the symbolic target. I consider GCHQ just as guilty.”

Judge Bobbie Cheema-Grubb said on Monday that Bowles had carried out a “politically motivated attack” that was driven by “anger and resentment” towards GCHQ and women.

He had researched the attack online beforehand, including studying the American “Unabomber” Ted Kaczynski, who mounted an anonymous bombing campaign from 1978 to 1995.

Bowles also looked up attacks on women and white supremacy.

In one of his police interviews, Bowles said: “The system is rigged. I believe the intelligence community helps ensure this rigging, this view has been reinforced by my time working at GCHQ.”

Penny also said Bowles described himself as a “terrorist” after the attack, saying to one witness: “I make a pretty s*** terrorist, don’t I?”