Three of the four Muslim converts convicted of a post-9/11 plot to bomb New York synagogues and shoot down planes were ordered to be released from prison by a judge who declared their 25-year sentences “unduly harsh and unjust” — and blamed the FBI for radicalizing them.

Onta Williams, David Williams and Laguerre Payen — three of the four men who became known as the “Newburgh Four” — were granted their request for compassionate release by US District Judge Colleen McMahon on Thursday.

In her ruling, McMahon slammed the FBI’s sting operation that snared the men, whom she wrote were “hapless, easily manipulated and penurious petty criminals” that were set up by the feds and their unreliable informant.

“The real lead conspirator was the United States,” McMahon wrote.