Defense Secretary Chuck Hagel quietly notified Congress last week that the military is set to transfer six Guantanamo Bay prisoners to Uruguay as soon as next month, The New York Times revealed Wednesday. The deal has been waiting for Mr. Hagel’s approval since March, but stalled after the Obama administration received a wave of backlash for releasing five Taliban detainees to Qatar in exchange for the release Army Sgt. Bowe Bergdahl. The administration did not give Congress 30-days notice in that deal, but argued it was still legal because any delay could have risked Sgt. Bergdahl’s life. Of the six...