Something really bad happened last week.

Either the United States, with help from Great Britain, released four dangerous terrorists from custody, or four men have been illegally and inappropriately detained at Guantanamo Bay for as much as three years.

On Jan. 26, according to the Guardian newspaper, four Britons who had been held by U.S. forces without due process or trial were released after questioning by Scotland Yard.

Two of the men were captured in Pakistan, one was taken in Zambia and the third was arrested in Afghanistan. They have languished in prison since, denied contact with their families or real legal representation. It took high-level negotiations between the United States and Great Britain, our staunchest ally in the war in Iraq, to free the men.

Five other Britons held at Guantanamo Bay were also released in March and returned to Great Britain.

If these men were not British, if they were citizens of a country with a less-developed legal tradition or that did not support the war efforts of the United States, would they still be in prison?

Apparently, the four men posed no serious threat to U.S. or British security. After years of confinment and interrogation, Scotland Yard cut them loose after only a day of questioning. No charges were filed, and, according to The Associated Press, none are likely.

It’s a stark example of why judicial and congressional oversight are necessary as the United States continues to round up and detain people from around the world. Hundreds of prisoners, and perhaps even more, cannot be held indefinitely in legal limbo, waiting for the good graces of the U.S. government or the intervention of their home country.