“This whole deal may have been a test to see how far the administration can actually push it, and if Congress doesn’t fight back they will feel more empowered to move forward with additional transfers,” said one senior GOP senate aide close to the issue. “They’ve lined up all the dominoes to be able to move a lot more detainees out of Guantanamo and this could be just the beginning.”

On Saturday, only three days after announcing the complete withdrawal of U.S. troops from Afghanistan by 2017, the White House revealed that it was releasing the Taliban commanders in exchange for Bergdahl. The law requires 30 days’ advance Congressional notification before such a release from Guantanamo. But it was simply not workable in this case, White House officials, said; the soldier’s health was failing, and the Qatari-brokered deal for the prisoner swap unfolded too quickly.

Lawmakers’ surprise fueled their confusion and skepticism about the deal—especially since the on-again off-again negotiations for Bergdahl were an open secret, dating back years. GOP leaders, in particular, were offended that they received calls from their Democratic counterparts and administration officials only after Bergdahl’s release was reported in the news.