Even though it has been several years since any new detainees have been transferred to Guantanamo Bay, the intelligence extracted from them is still proving its worth—in major and surprising ways.

Buried in the flood of information on the extraordinary operation to locate and kill Osama bin Laden is the critical role of strategic interrogations of detainees, including those at Guantanamo. According to a number of published reports, Gitmo detainees provided key pieces of information that ultimately lead to the location and death of Osama bin Laden.

Those reports are confirmed, in large part, by the government. A senior official who briefed the press early this morning explained that “detainees in the post-9/11 period flagged for us individuals who may have been providing direct support to bin Laden and his deputy, [Ayman al-] Zawahiri, after their escape from Afghanistan.”

He continued: “One courier in particular had our constant attention. Detainees gave us his nom de guerre, or his nickname, and identified him as both a protégé of Khalid Sheikh Mohammed, the mastermind of September 11, and a trusted assistant of Abu Faraj al-Libbi, the former number three of al-Qaeda who was captured in 2005.” The United States obtained this information four years ago, the official stated.

One more crucial fact: According to the “detainees” (note the plural), this individual was “one of the few al-Qaeda couriers trusted by bin Laden.”

Think about that: This lead was developed during the Bush Administration, most likely from al-Qaeda associates picked up and transferred to Guantanamo and subject to interrogations that critics have repeatedly deemed to be pointless in terms of intelligence value. Whether these detainees remain at Guantanamo is an open question.

Even at this early point in the news cycle, it is reasonably clear that detainees at Guantanamo (and perhaps elsewhere, such as those formerly in CIA custody and now at Guantanamo) who agreed to long-term lawful strategic interrogation gave the critical nuggets of information that put in motion a series of events that led to bin Laden’s death.

For years, we have heard that strategic interrogation of detainees at Guantanamo was worthless, that the information is (at best) stale and almost certainly of dubious reliability. The most strident call such interrogations illegal.

Even some senior intelligence officials in the Department of Defense were often dismissive of the value of intelligence gleaned at Guantanamo.

Could there be any clearer proof that those critics are just plain wrong?

Intelligence-gathering and analysis has been the backbone of our many known (and unknown) counterterrorism successes since 9/11. A key part of that has been the role of real-time tactical interrogations and long-term strategic interrogation.

The information gleaned from those interrogations is fed into a vast and interconnected intelligence network that has resulted in remarkable achievements in “connecting the dots,” sometimes over a period of years, to disable plots and kill or capture terrorists.

That intelligence has enabled the U.S., under the leadership of both Presidents Bush and Obama, to stay on the offensive while remaining vigilant to the very real threats that confront the nation every day. Yesterday, once again, proves the value of a long-term, lawful terrorist interrogation program.

Charles D. “Cully” Stimson is a Senior Legal Fellow at The Heritage Foundation and former Deputy Assistant Secretary of Defense for Detainee Affairs (2006–2007). While in office, Stimson oversaw the re-writing of the Army Field Manual on Interrogations and the movement of the CIA high-value detainees to Guantanamo.