The U.S. base in Guantánamo Bay, in southeast Cuba, is more than 100 years old and has about 4,200 residents. The prison opened on Jan. 11, 2002, with the arrival of 20 detainees from the war against Al Qaeda and the Taliban in Afghanistan. Over the years, the U.S. military has held about 780 men and boys there, with the Bush administration repatriating about 500 of them. Today the operation has a staff of 800 soldiers and civilians — more than 50 U.S. government workers for each detainee. In the past year, the Trump administration has used the base as a transit hub for federal prisoners, including about 775 migrants held there for days or weeks. In a secret operation this month, a U.S. military cargo plane brought the deposed Venezuelan President Nicolás Maduro and his wife, Cilia Flores, to the base on the day of their capture by U.S. forces. The remaining 15 wartime prisoners at Guantánamo, ages 46 to 64, have been held in a single building since last year and are rarely seen by anybody but their guards and lawyers. Khalid Shaikh Mohammed, who is accused of being the mastermind of the Sept. 11 plot, has been there for nearly 20 years and has not yet faced trial. Tens of thousands of troops have served there on temporary deployments. Pete Hegseth, the defense secretary, did so from 2004 to 2005. The last study of the costs of running the prison put the figure at more than $13 million per year for each prisoner in 2019. Note: Read more about the horrors of Guantánamo Bay. Learn more about US torture programs in our comprehensive Military-Intelligence Corruption Information Center. For more, read our concise summaries of news articles on corruption in the military and in the prison system. - New York Times