The effects of solitary confinement are insidious.

The military court martial for Bradley Manning, the army private accused of leaking thousands of classified diplomatic cables to WikiLeaks, has at last begun. Although he could face life in prison for a crime of conscience, Manning must feel at least some relief that his pre-trial confinement has come to an end.

While awaiting trial, Manning was for long stretches subjected to 23 hours of solitary confinement a day, denied clothing, sheets, or a pillow, and prevented from exercising in his barren white cell. Manning is not an accused terrorist, murderer, or mastermind. In 2010, he was charged with revealing to WikiLeaks classified government records, dating back to the mid-2000s, about the wars in Iraq and Afghanistan. Manning’s admirers have ascribed his actions to his legal and national sense of duty to expose war crimes, as some of the released documents expose American military personnel violating international humanitarian law.

Yet despite this—and the fact that Manning is to be presumed innocent until proven otherwise—the army private was jailed in debilitating solitary confinement, perhaps as retribution for his political beliefs or as an attempt at behavior modification, or for whatever other reason the court may have decided.

Solitary confinement cells were first experimented with by a group of Quakers hoping to reduce the corruption present in overpopulated jails and promote reflection and mental rehabilitation among prisoners. But the Quakers quickly did away with the practice due to the deteriorating mental state of prisoners. Since then, endless testimonies, papers, and accounts have argued what was clear to these 19th-century pioneers: Solitary confinement is cruel, inhumane, and mentally torturous. Charles Dickens, who had developed an interested in the prison system, visited this early attempt at solitary confinement and concluded it to be “immeasurably worse than any torture of the body… because its wounds are not upon the surface, and it extorts few cries that human ears can hear; therefore I the more denounce it, as a secret punishment which slumbering humanity is not roused up to stay.”

It is not just the religious or the literary who oppose such prison conditions. Senator John McCain, a former POW and on many issues an unrepentant hawk, has been an outspoken opponent of solitary confinement. And the U.S. Supreme Court has come close to following in the footsteps of the Geneva Convention and United Nations in declaring the practice unconstitutional.

Yet presently, the United States continues to condemn nearly 80,000 citizens to solitary confinement, many of whom are like Bradley Manning and have not yet been convicted of any crime. In fact, even those who are serving out an actual sentence often are not guilty of any prison offense, such as drug dealing or fighting, that could theoretically justify their separation from other prisoners.

Many solitary prisoners exhibit model behavior during their incarceration and participate in higher education courses and religious services. Yet despite their obedience, for many there is no escaping solitary confinement, which accounts for 39 percent of suicides among inmates. Manning has admitted that following a bout of suicidal thoughts, when he fashioned a noose out of bed sheets, he was reduced to sleeping naked without any bedding, long after these thoughts had passed. Medical personnel now administer anti-depressants to Manning on a regular basis to prevent the mental deterioration that is characteristic of inmates in solitary confinement. Military officials have defended Manning’s treatment, claiming that he is considered a maximum-security prisoner and both a threat to himself and others.

Unfortunately, this is not a new trend in American prisons. Wen Ho Lee, the Taiwanese-American nuclear scientist accused of selling U.S. nuclear secrets to China, was held in solitary confinement when charged with violation of the Atomic Energy Act among 59 other charges, 58 of which were later dropped. The Justice Department so strongly believed that it had correctly identified the guilty party that it presented false information to the judge at the initial bail hearing, causing Lee to be sent to solitary confinement, despite the judge’s request for a less severe alternative. The presiding judge eventually extended an apology to Lee.

Ultimately, whether one is truly innocent or just innocent until proven guilty, the United States must treat its inmates and convicts with at least a bare minimum amount of respect and humanity. This must extend from accused Americans like Manning to detained foreigners such as those held in Guantanamo Bay if the United States hopes for its citizens and soldiers abroad to receive the same.

Lizzie Rajasingh is an intern at Foreign Policy in Focus.