The district court in Alexandria, Virginia, on Tuesday sentenced former Air Force intelligence analyst Daniel Hale to nearly four years in prison, the Responsible Statecraft website reported.

He was charged under the Espionage Act for leaking secret documents about the Obama administration's clandestine drone strike operations in 2014 and 2015.

The documents, which were published in October 2015 by The Intercept, revealed the horrific details of the US drone war in Somalia, Yemen and Afghanistan, as well as a procedures manual used by the US government to add individuals to its terrorism watch lists and locate them. In March, Hale pleaded guilty to one count of violating the Espionage Act.

The documents leaked by Hale reveal that the Obama administration set up an out-of-court process to select its targets and kill them, often based on scant evidence that the target posed a " continuing and imminent threat."
They also revealed that more civilians were killed in the strikes than previously thought. During the five-month special operations drone campaign in Afghanistan, nearly 90 % of those killed by U.S. airstrikes were not the intended targets.

In the end, Daniel Hale's revelations highlighted the scale, illegality and unnecessarily destructive nature of Obama's covert drone war.