As a former career intelligence professional, I have a profound appreciation for the value of intelligence. Intelligence disrupts terrorist plots and thwarts attacks. Intelligence saves lives.

In full accordance with the law - and in order to prevent terrorist attacks on the United States and to save American lives - the United States government conducts targeted strikes against specific al-Qa'ida terrorists, sometimes using remotely piloted aircraft, often referred to publicly as drones.

Al-Qa'ida does not follow a traditional command structure, wear uniforms, carry its arms openly, or mass its troops at the borders of the nations it attacks. Nonetheless, it possesses the demonstrated capability to strike with little notice and cause significant civilian or military casualties.

I will not, nor will I ever, publicly divulge sensitive intelligence sources and methods. For when that happens, our national security is endangered and lives can be lost.

Is real, it is serious, it is growing, and it constitutes one of the greatest threats to our national security and, indeed, to global security.

A lot of things look good on an academic's blackboard in terms of the actions that need to be taken. It's almost like a football coach, when you draw the X's and O's: Every play that is chalked on that board goes for a touchdown. Well, there are a lot of yards to be made between the line of scrimmage and the touchdown.

The risk of just one terrorist with just one nuclear weapon is a risk we simply cannot afford to take.