More than a decade after the Guantanamo Bay prison saw its first detainees, the man who established it says the center "should have never been opened," and it's time for the government to shut it down.

Michael Lehnert, the Marine major general charged with building the first 100 prison cells at the Cuban prison, says he knew early on that Guantanamo was a mistake. "I became more and more convinced that many of the detainees should never have been sent in the first place," Lehnert, now retired, wrote in a column published Thursday in the Detroit Free Press. "They had little intelligence value, and there was insufficient evidence linking them to war crimes."

While Lehnert believes some detainees should be transferred to the U.S. for prosecution, the majority of Guantanamo prisoners shouldn't be held there. Supporters of keeping the prison in operation say released detainees could retaliate against the U.S. Lehnert says there is no guarantee that any detainee who is set free will not plan an attack against the nation, "just as we cannot promise that any U.S. criminal released back into society will never commit another crime."

The retired general says maintaining the detention center threatens national security because it "validates every negative perception of the United States."

In 2009, Lehnert publicly expressed his disappointment with reports of poor treatment of detainees by U.S. military personnel. For him, humane treatment was top priority the day the prison camp opened. "I think we lost the moral high ground," he told the Los Angeles Times. "For those who do not think much of the moral high ground, that is not that significant. But for those who think our standing in the international community is important, we need to stand for American values. You have to walk the walk, talk the talk."

President Obama promised to do just that in 2008 when, as a presidential candidate, he vowed to close the prison if elected. Shortly after he was sworn in, he signed an executive order mandating that Guantanamo be closed within a year, but a genuine push never got off the ground, prompting many to call Obama's plan a "broken promise."

This week, Congress is scrambling to pass a defense authorization bill before the holidays, one that includes language allowing the president more flexibility to transfer detainees from Guantanamo to other countries. To lawmakers, the retired general says, "it is time to close Guantanamo."