(CNN) -- Even with the war in Afghanistan winding down, the United States will continue its fight against al Qaeda and its affiliates, wherever they may be, by using all means available in an armed conflict, the Pentagon's chief lawyer said Friday.
"We must counter al Qaeda in the places where it seeks to establish safe haven and prevent it from reconstituting in others. To do this, we must utilize every national security element of our government," said Jeh Johnson, the top lawyer for the U.S. Defense Department, at a speech Friday at Oxford University in England.
Those elements of force include unmanned aerial vehicles, widely referred to as drones, to kill suspected terrorists hiding out in the ungoverned regions of Pakistan, in Yemen and elsewhere, as well as the indefinite detention of extremists caught on the battlefield.
Johnson said that some legal scholars and commentators refer to those means as extrajudicial killing and criticize the U.S. government for holding individuals without formal charges. But he argued that the tools used against al Qaeda in what he called "an unconventional conflict" are legitimate. He said that capture and detention by the military are parts of war, adding: "We employ lethal force, but in a manner consistent with the law of war principles of proportionality, necessity and distinction."
Johnson said that is consistent with the Geneva Conventions governing conflict and that all three branches of the U.S. government have endorsed the efforts used to combat al Qaeda.