I find this argument thoroughly unconvincing. One could as easily argue that the purpose of torture is to satisfy our strategic objectives in Iraq and Afghanistan. The proper answer to which is, who cares? It's wrong.
Consider the results of the firebombing of a city for which the justification was sapping the will of civilians to make war:
"We saw terrible things: cremated adults shrunk to the size of small children, pieces of arms and legs, dead people, whole families burnt to death, burning people ran to and fro, burnt coaches filled with civilian refugees, dead rescuers and soldiers, many were calling and looking for their children and families, and fire everywhere, everywhere fire, and all the time the hot wind of the firestorm threw people back into the burning houses they were trying to escape from.
I cannot forget these terrible details. I can never forget them.
Now my rnother possessed only a little bag with our identity papers. The basket with the twins had disappeared and then suddenly my older sister vanished too . Although my rnother looked for her immediately it was in vain. The last hours af this night we found shelter in the cellar of a hospital nearby surrounded by crying and dying people. In the next morning we looked for our sister and the twins but without success. The house where we lived was only a burning ruin. The house where our twins were left we could not go in. Soldiers said everyone was burnt to death and we never saw my two baby sisters again."
"Only someone who has been in such a sea of flame can judge what it means to breathe in such an oxygen-deficient atmosphere . . . while battling against terribly hot, constantly changing currents of fire and air. My lungs were heaving. My knees began to turn weak. It was horrifying. Some individuals, especially old people, started to hang back. They would sit down apathetically on the street and just perish of asphyxiation."
"Margaret Freyer, for instance, ascribed her survival once she had left the doomed cellar on the Struvestrasse--the streets were already like ovens--to the fact that she had chosen to wear knee boots when she went outside that winter night to visit a friend. In the heat, the tar on the streets melted. Others who tried to flee through this viscous quagmire rapidly lost their slip-on shoes, even their lace-ups, which stuck in the tar. Their feet were so badly burned they could no longer move. They died."
"Hundreds of desperate human beings, some already on fire, found their way to the Altmarkt. They plunged gratefully into the apparent safety of the cool, plentiful water. As the night wore on, however, the searing air of the surrounding conflagrations and the accumulated effect of all the burning human beings who had crowded into the reservoir began to have an effect. The heat within became intolerable, the air unbreathable. In the tank, hosts of survivors, many injured, many poor or nonswimmers, tried to clamber out again, only to find that the Altmarkt reservoir had not been built as a swimming pool. There were no bars or handles, no ladders. On the contrary, the sides of the reservoir were smooth cement, upon which it proved almost impossible to obtain a purchase.
. . . a very few of the strongest swimmers and nimblest climbers managed to get back out. The great reservoir in the Altmarkt was both a terrible place of struggle that night and . . . a watery grave for hundreds of unlucky people.
The next day, when rescue gangs cleared their way through the square, half the huge quantity of water had evaporated. A macabre ring of charred corpses surrounded the reservoir; those were the bodies of those who had not quite made it to the reservoir before they burned to death, or were overcome by fumes. In the Seidlitzer Platz tank, which was about fifty feet square, would-be survivors had crowded the water up to the rim--it was shallow enough to stand upright--until it could take no more. The next day they were still there, most still packed next to each other in orderly fashion. All dead of asphyxiation.
In smaller tanks, the water became so hot that the people in them were literally cooked."
These are mostly taken from Frederick Taylor's Dresden, which I highly don't recommend buying unless you enjoy vomiting. Keep in mind that these are the eyewitness accounts; presumably those who didn't survive saw even worse.
I simply cannot believe that we did this more in sorrow than in anger.