For make no mistake: evil does exist in the world. A non-violent movement could not have halted Hitler’s armies. Negotiations cannot convince al Qaeda’s leaders to lay down their arms. To say that force is sometimes necessary is not a call to cynicism – it is a recognition of history; the imperfections of man and the limits of reason. So yes, the instruments of war do have a role to play in preserving the peace. And yet this truth must coexist with another – that no matter how justified, war promises human tragedy.

The soldier’s courage and sacrifice is full of glory, expressing devotion to country, to cause and to comrades in arms. But war itself is never glorious, and we must never trumpet it as such.So part of our challenge is reconciling these two seemingly irreconcilable truths – that war is sometimes necessary, and war is at some level an expression of human feelings. Concretely, we must direct our effort to the task that President Kennedy called for long ago. “

Let us focus,” he said, “on a more practical, more attainable peace, based not on a sudden revolution in human nature but on a gradual evolution in human institutions.”_Barack Obama