Khalid Sheik Mohammed, the man who bragged that he ran the Sept. 11, 2001, terror attacks “from A to Z,” has written President Barack Obama about his views on the situation in Gaza and other current events.

If the letter clears a review for “non-legal” communications by prison headquarters, U.S. troops can put a postage stamp on it and drop it in the mail to the commander-in-chief.

Mohammed’s defense attorney, David Nevin, disclosed the existence of the letter during a news conference on Thursday. In the letter, Mohammed complains about “Muslim oppression at the hands of the West in general and the United States in particular,” according to Nevin. He shares his views on what happened in Iraq during the period of U.S. sanctions and “events in Palestine and Gaza over the years,” Nevin said.

Nevin said he doubts the letter contains classified information — although he noted that the president has the sweeping power to declassify it.

After Mohammed’s capture in Pakistan in March 2003, the CIA held the alleged mass murderer in its secret overseas prison network, where the agency broke his will with 183 rounds of waterboarding and other, as-yet undisclosed “enhanced interrogation techniques.”

Since his arrival at Guantánamo, he’s been held in a prison called Camp 7 that is run by a secret military unit, Task Force Platinum. Everything Mohammed says and does is presumptively classified.

On Saturday, as the prosecution and defense teams for the 9/11 case were leaving Guantánamo for Andrews Air Force Base, where the White House parks Air Force One, Army Lt. Col. Myles B. Caggins III said that the military lets each Camp 7 captive mail at most two letters and four postcards a month as “non-legal mail.”

Those correspondences are different than the International Red Cross messages that the global, Geneva-based prisoners-rights group delivers to families around the world (the U.S. military censors those, too). “Legal mail” is correspondence between the Camp 7 captives and their lawyers through a Privileged Review Team system supervised by the war court judge, Army Col. James L. Pohl in collaboration with the prison.

The third category is “non-legal mail,” such as the letter from Mohammed to Obama. And those “are reviewed for security purposes,” according to Caggins, by the Detention Center directorate responsible for intelligence operations, called the J-2.

Because prisoners can’t have postage stamps, Caggins said, the detention center staff will stick a stamp on it and send it “through the U.S. Postal System.”

Classified information can’t go through ordinary mail. That means anything Mohammed writes Obama that the prison intelligence unit considers a secret would be redacted before it reaches 1600 Pennsylvania Ave.

Earlier, the chief war crimes prosecutor, Army Brig. Gen. Mark Martins, who has charged Mohammed and four other men with the deaths of 2,976 people on 9/11, said all U.S. national-security lockups have “special administrative measures” that make sure communications with the outside world “are carefully managed.”

“Those restrictions balance very important concerns of security, fairness, access to counsel,” Martins said.

Carol Rosenberg tweets @carolrosenberg on Twitter.