Why is torture justified for national security?

Before answering the question "why is torture justified for national security," this "educator" feels compelled to emphasize that what follows is a justification for torture that does not recommend nor endorse the use of torture under any circumstance.
The debate over the use of "enhanced interrogation techniques," such as waterboarding and sleep deprivation, arose in the context of the treatment of captured terrorists and Iraqi security forces following the terrorist attacks of September 11, 2001 and the 2003 invasion of Iraq. Many of the captured individuals were subjected to forms of treatment and interrogation that many Americans viewed as constituting torture. Whether that treatment was justified as a matter of national security has been widely and fiercely debated, including in Congress, and no definitive resolution, at least politically, is in sight.
The reason for the continued divisiveness of the issue of torture is the belief that, under certain extenuating circumstances, torture is necessary to prevent future terrorist attacks. There exists in policy and legal discussions on the use of "enhanced interrogation techniques" and other activities that indisputably constitute torture (such as physical beating, mock execution, and so on) the notion of what is called "the ticking time bomb scenario.” In other words, if the use of torture against a captive terrorist or criminal can extract information that will save lives by compelling the captive to provide information on the details of a pending terrorist attack, then the use of torture will have been justified. In this sense, torture is justified for national security reasons. Especially if that “ticking time bomb” is in the form of a weapon of mass destruction, such as a nuclear bomb, chemical or biological weapon, or so-called “dirty bomb,” then the use of torture on a captured terrorist is considered by some to be justified.