Recent history demonstrates that if President Barack Obama, arguably the most powerful person on planet Earth, wants to prioritize almost anything – from pardoning 46 convicted drug felons to bombing a foreign country without the consent of Congress – little can stand in his way. Why, then, is Shaker Aamer not home in London with his wife and four children?

Aamer is the last British resident to be detained without trial in Guantánamo Bay and he has never been charged with a single offense. In 2007, he was cleared for release by the Bush Administration; in 2009, six US intelligence agencies unanimously agreed that Shaker should be released. In January 2015, British Prime Minster David Cameron personally raised Shaker’s plight with President Obama, who promised that he would “prioritize” the case.

On Thursday, we came a little closer to understanding the reason that Aamer’s youngest child, Faris – who was born on Valentine’s Day 2002, the day that Aamer was rendered to the detention center at Guantánamo Bay – has never even met his father. The Guardian revealed that “the Pentagon [is] blocking Guantánamo deals to return Shaker Aamer and other cleared detainees.” President Obama, it seems, has personally ordered Aamer’s release, and his subordinates have ignored and thwarted his order.

However, Article II, Section 2 of the US Constitution provides that the “President shall be Commander in Chief of the Army and Navy of the United States”. Under Article 90 of the Uniform Code of Military Justice, to disobey an order in peacetime is punishable by life in prison. If we believe the Pentagon theory that we are involved in a “Global War on Terror”, then there is an ongoing war, and the punishment for disobeying orders is death.

I certainly don’t advocate that General Martin Dempsey, the Chairman of the Joint Chiefs of Staff named by the Guardian as an opponent of President Obama’s order, be shot at dawn. However, the contravention of the president’s orders indicates that there is a profound problem with the state of democracy in America. The military is not a democratic institution; a soldier takes an oath to follow orders. When a military officer simply chooses not to follow the clear order of the president, it is a slap in the face for the American system of government.

What makes General Dempsey qualified to be the ultimate arbiter of due process? It is certainly not his intimate knowledge of the prisoners who he has blackballed. I am not sure General Dempsey has ever even been to Guantánamo; I have, some 35 times. Certainly, he has never met Shaker Aamer; I have, some 35 times. If General Dempsey took the time to learn the facts, he would discover that Aamer is no more a terrorist than the general himself is. Aamer loudly protests his detention without trial; all he wants is to be back with his children in London.

I also represent the second detainee whose release Dempsey is blocking, Ahmed Abdul Aziz. He was cleared five years ago, and his transfer to Mauritania was agreed by the State Department in 2013. Aziz, too, merely wants to be back with his wife and his son.

In addition to being General Dempsey’s commander-in-chief, President Obama is a lawyer: he knows that the legal black hole that is Guantánamo is a blot on America’s record; he recognizes that the very word “Guantánamo” now acts as a recruiting sergeant for the extremists around the world. In 2004, a “Senior Defense Intelligence Agency Official” told journalist David Rose that for every detainee in Guantánamo Bay, we had spawned 10 new supporters of terrorism. More than 11 years later, sadly the multiplier is far larger.

One of the reasons that Guantánamo is such a blot on America’s reputation and such a good recruiting tool is the un-American and arbitrary detention of detainees without trial. And it is even more offensive to the rule of law for the US to to clear a prisoner for release twice, and then continue to hold him for year upon year because some military officer decides that he knows best but will not come clean in public and explain himself.

President Obama should certainly call General Dempsey into the Oval Office and read him the riot act. And though Obama is right to try to close Guantánamo Bay in general, the broader issue at stake is whether he is willing to allow the Pentagon to undermine the very essence of the US constitution. The president has given an order to the military; they need to obey it.