By CNN Senior National Security Producer Charley Keyes
The tropical sun burns hot on Guantanamo Bay naval base. And so does the international spotlight on how - and how long - the U.S. will continue to hold its worst-of-the-worst enemies 10 years after the September 11 attacks.
Among the detainees are the alleged architects of the 9/11 attacks and the near-sinking of the USS Cole as well as scores of suspected "enemy combatants" captured on the battlefields of Iraq and Afghanistan.
This September 11 will resemble every other day for the 171 men held in the detention camps, and the more than 1,100 U.S. military standing guard at Gitmo, as the base is known.
It is the oldest American military installation outside the United States, 45 square miles carved out of Cuba, whose hills are visible from the fenced perimeter.
On next Sunday - as they do each day - soldiers and sailors will turn to the nearest U.S. flag and stand and salute, and "The Star-Spangled Banner" will blare from loudspeakers at 8 a.m. sharp.
"On 9/11 hopefully it will be a calm day like it was last year," said Col. Donnie Thomas, who has been at Guantanamo for 19 months and serves as commander of the Joint Detention Group.
Analysis by CNN's Paul Cruickshank and Tim Lister
If Younis al-Mauretani has been arrested in Pakistan, it is another significant blow against the operational ambitions of al Qaeda. Counter-terrorism analysts say he had become a key planner for the group in recent years - and he appears to have had direct contact with Osama bin Laden.
Like many in al Qaeda, al-Mauritania adopted his country of origin as his last name. He was from the sparsely populated desert state of Mauritania in north-west Africa. Al Qaeda has recruited extensively from Mauritania and neighboring countries, where al Qaeda in the Islamic Maghreb now has a foothold.
Al-Mauretani's stature within al Qaeda appears to have grown in the last two years. According to European intelligence officials, he was involved in planning attacks in Europe in the fall of 2010. Fears that such attacks would materialize led the U.S. State Department to issue a travel alert in October 2010. The alert said that "current information suggests that al Qaeda and affiliated organizations continue to plan terrorist attacks." It added that some European governments were warning of "heightened threat conditions."