By the time Barack Obama became president of the United States in 2009, two-thirds of the prisoners at Guantánamo Bay had already been released by George Bush. With 242 remaining, Obama promised to close the prison camp by January 2010. In January 2016, in his final year as president, there are still around 100 prisoners.

As early as 2007, then Illinois senator and Democrat presidential candidate Barack Obama declared that “As President, I will close Guantanamo, reject the Military Commissions Act, and adhere to the Geneva Conventions.” The pledge to close Guantánamo was a central plank of his election campaign.

One of his very first actions upon becoming president, on 22 January 2009, was to sign an executive order to review the status of prisoners, impose a moratorium on military tribunals and to close Guantánamo “as soon as practicable, and no later than 1 year from the date…