A federal judge has decided to set free former al Qaeda officer Najibullah Zazi, effectively sentencing him to time served. In so doing, federal judge Raymond J. Dearie served U.S. national security on Friday.

While time served might seem like an odd sentence for a man who conspired to unleash multiple bombs on the New York City subway system in 2009, his release does more for national security than would his continued detention. In their submissions to the court, federal prosecutors described Zazi as having transformed during his ten years in prison.