And, we have publicly stated that our goal in this conflict is to “disrupt, dismantle, and ensure a lasting defeat of al Qaeda and violent extremist affiliates.”

Some legal scholars and commentators in our country brand the detention by the military of members of al Qaeda as “indefinite detention without charges.” Some refer to targeted lethal force against known, identified individual members of al Qaeda as “extrajudicial killing.”

Viewed within the context of law enforcement or criminal justice, where no person is sentenced to death or prison without an indictment, an arraignment, and a trial before an impartial judge or jury, these characterizations might be understandable.

Viewed within the context of conventional armed conflict -- as they should be -- capture, detention and lethal force are traditional practices as old as armies. Capture and detention by the military are part and parcel of armed conflict. We employ weapons of war against al Qaeda, but in a manner consistent with the law of war. We employ lethal force, but in a manner consistent with the law of war principles of proportionality, necessity and distinction. We detain those who are part of al Qaeda, but in a manner consistent with Common Article 3 of the Geneva Conventions and all other applicable law.

But, now that efforts by the U.S. military against al Qaeda are in their 12th year, we must also ask ourselves: how will this conflict end? It is an unconventional conflict, against an unconventional enemy, and will not end in conventional terms.

Conventional conflicts in history tend to have had conventional endings.

Two hundred years ago, our two Nations fought the War of 1812. The United States lost many battles, Washington, DC was captured, and the White House was set ablaze. By the winter of 1814 British and American forces had strengthened their forts and fleets, and assumed that fighting would resume between them in the spring. But, the war ended when British and American diplomats in Belgium came to a peace agreement on December 24, 1814. Diplomats from both sides then joined together in a Christmas celebration at Ghent cathedral. Less than eight weeks later, the U.S. Senate provided advice and consent to that peace treaty, which for the United States legally and formally terminated the conflict.

In the American Civil War, the Battle of Appomattox was the final engagement of Confederate General Robert E. Lee’s great Army of Northern Virginia, and one of the last battles of that war. After four years of war, General Lee recognized that “[i]t would be useless and therefore cruel to provoke the further effusion of blood.” Three days later the Army of Northern Virginia surrendered. Lee’s army then marched to the field in front of Appomattox Court House, and, division by division, deployed into line, stacked their arms, folded their colors, and walked home empty-handed.

The last day of the First World War was November 11, 1918, when an armistice was signed at 5:00 a.m. in a railroad carriage in France, and a ceasefire took effect on the eleventh hour of the eleventh day of the eleventh month of 1918.

The Second World War concluded in the Pacific theater in August 1945, with a ceremony that took place on the deck of the USS Missouri.

During the Gulf War of 1991, one week after Saddam Hussein’s forces set fire to oil wells as they were driven out of Kuwait, U.S. General Schwarzkopf sat down with Iraqi military leaders under a tent in a stretch of the occupied Iraqi desert a few miles from the Kuwaiti border. General Schwarzkopf wanted to keep discussions simple; he told his advisors: “I just want to get my soldiers home as fast as possible . . . I want no ceremonies, no handshakes.” In the space of two hours they had negotiated the terms of a permanent cease-fire to end the First Gulf War.

We cannot and should not expect al Qaeda and its associated forces to all surrender, all lay down their weapons in an open field, or to sign a peace treaty with us. They are terrorist organizations. Nor can we capture or kill every last terrorist who claims an affiliation with al Qaeda.

I am aware of studies that suggest that many “terrorist” organizations eventually denounce terrorism and violence, and seek to address their grievances through some form of reconciliation or participation in a political process.

Al Qaeda is not in that category.

Al Qaeda’s radical and absurd goals have included global domination through a violent Islamic caliphate, terrorizing the United States and other western nations from retreating from the world stage, and the destruction of Israel. There is no compromise or political bargain that can be struck with those who pursue such aims.

In the current conflict with al Qaeda, I can offer no prediction about when this conflict will end, or whether we are, as Winston Churchill described it, near the “beginning of the end.”

I do believe that on the present course, there will come a tipping point – a tipping point at which so many of the leaders and operatives of al Qaeda and its affiliates have been killed or captured, and the group is no longer able to attempt or launch a strategic attack against the United States, such that al Qaeda as we know it, the organization that our Congress authorized the military to pursue in 2001, has been effectively destroyed.

At that point, we must be able to say to ourselves that our efforts should no longer be considered an “armed conflict” against al Qaeda and its associated forces; rather, a counterterrorism effort against individuals who are the scattered remnants of al Qaeda, or are parts of groups unaffiliated with al Qaeda, for which the law enforcement and intelligence resources of our government are principally responsible, in cooperation with the international community – with our military assets available in reserve to address continuing and imminent terrorist threats.

At that point we will also need to face the question of what to do with any members of al Qaeda who still remain in U.S. military detention without a criminal conviction and sentence. In general, the military's authority to detain ends with the “cessation of active hostilities.”

For this particular conflict, all I can say today is that we should look to conventional legal principles to supply the answer, and that both our Nations faced similar challenging questions after the cessation of hostilities in World War II, and our governments delayed the release of some Nazi German prisoners of war.

For now, we must continue our efforts to disrupt, dismantle and ensure a lasting defeat of al Qaeda. Though severely degraded, al Qaeda remains a threat to the citizens of the United States, the United Kingdom and other nations. We must disrupt al Qaeda’s terrorist attack planning before it gets anywhere near our homeland or our citizens. 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, and work closely with our friends and allies like the United Kingdom and others.

Finally, it was a warfighting four-star general who reminded me, as I previewed these remarks for him, that none of this will ever be possible if we fail to understand and address what attracts a young man to an organization like al Qaeda in the first place. Al Qaeda claims to represent the interests of all Muslims. By word and deed, we must stand with the millions of people within the Muslim world who reject Al Qaeda as a marginalized, extreme and violent organization that does not represent the Muslim values of peace and brotherhood. For, if al Qaeda can recruit new terrorists to its cause faster than we can kill or capture them, we fight an endless, hopeless battle that only perpetuates a downward spiral of hate, recrimination, violence and fear.

“War” must be regarded as a finite, extraordinary and unnatural state of affairs. War permits one man – if he is a “privileged belligerent,” consistent with the laws of war -- to kill another. War violates the natural order of things, in which children bury their parents; in war parents bury their children. In its 12th year, we must not accept the current conflict, and all that it entails, as the “new normal.” Peace must be regarded as the norm toward which the human race continually strives.

Right here at Oxford you have the excellent work of the Changing Character of War program: leading scholars committed to the study of war, who have observed that analyzing war in terms of a continuum of armed conflict -- where military force is used at various points without a distinct break between war and peace -- is counterproductive. Such an approach, they argue, results in an erosion of “any demarcation between war and peace,” the very effect of which is to create uncertainty about how to define war itself.

I did not go to Oxford. I am a graduate of a small, all-male historically black college in the southern part of the United States, Morehouse College. The guiding light for every Morehouse man is our most famous alumnus, Martin Luther King, who preached the inherent insanity of all wars. I am therefore a student and disciple of Dr. King – though I became an imperfect one the first time I gave legal approval for the use of military force. I accepted this conundrum when I took this job. But, I still carry with me the words from Dr. King: “Returning hate for hate multiples hate, adding deeper darkness to a night already devoid of stars … violence multiplies violence, and toughness multiplies toughness in a descending spiral of destruction … The chain reaction of evil—hate begetting hate, wars producing more wars—must be broken, or we shall be plunged into the dark abyss of annihilation.”

Thank you again for the honor and the opportunity to be in this special place, and thank you for listening to me.