From: Secret Underground Lair
Good post, Anthropoid. +1.
Thanks Chickenboy, however I should correct my (apparently) somewhat inaccurate claims about the overall conclusions of the U.S. Strategic Bombing Survey having been 'meh.' At least if we consider the consensus reached on the pages of Wikipedia to be sufficiently reliable--which I think it often is, and sometimes is not.
Wikipedia, for all its shortcomings never ceases to amaze. If nothing else that fact that it seems to be always growing; I do not recall this summary page existing before when I set out to familiarize myself with that report. Not that I've read the whole "several thousand pages(!?!)" but I do recall skimming through a PDF copy of one of the summary sections.
The bullet section down the wiki page a bit is particularly instructive as it outlines major areas of "Failure" and "Success" and here I can take some edification that my overall impression from memory is valid as, there were significant elements of German industry where strategic bombing failed to have any real impact.
Aviation production: "In 1944 the German air force is reported to have accepted a total of 39,807 aircraft of all types -- compared with 8,295 in 1939, or 15,596 in 1942 before the plants suffered any attack." According to the report, almost none of the aircraft produced in 1944 were used in combat and some may have been imaginary.
Armoured fighting vehicle production "reached its wartime peak in December 1944, when 1,854 tanks and armored vehicles were produced. This industry continued to have relatively high production through February 1945."
Ball bearings: "There is no evidence that the attacks on the ball-bearing industry had any measurable effect on essential war production."
"Secondary Campaigns" (Operation Chastise & Operation Crossbow): "The bombing of the launching sites being prepared for the V weapons delayed the use of V-l appreciably. The attacks on the V-weapon experimental station at Peenemunde, however, were not effective; V-l was already in production near Kassel and V-2 had also been moved to an underground plant. The breaking of the Mohne and the Eder dams, though the cost was small, also had limited effect."
Steel: The bombing greatly reduced production, but the resulting shortage had no contribution to the defeat.
Consumer goods: "In the early years of the war—the soft war period for Germany—civilian consumption remained high. Germans continued to try for both guns and butter. The German people entered the period of the air war well stocked with clothing and other consumer goods. Although most consumer goods became increasingly difficult to obtain, Survey studies show that fairly adequate supplies of clothing were available for those who had been bombed out until the last stages of disorganization. Food, though strictly rationed, was in nutritionally adequate supply throughout the war. The Germans' diet had about the same calories as the British."
As others have pointed out above, the scale of the strategic bombing campaigns in WWII or Vietnam were much larger than the present campaigns against ISIS, and of course many operational factors are tremendously different. I suppose the safest conclusion from history is: its complicated, and even when strategic bombing is effective, it may only be of limited effectiveness.
One last point worth mentioning, if memory serves, the section of this massive survey I paid the most attention to was the part about "breaking the will to fight" and the conclusion here was that the effect was not only zero but may well have (for a period of time) increased the solidarity, resourcefulness and resolve of the population to fight and win. The German bombing campaign against England certainly seems to have had that effect.
It may be that the present campaign against ISIS is constraining them, reducing their materiel resources and depleting their manpower, while at the same time filling them (and their would-be recruits from around the globe) with ever greater resolve to achieve their goals. Given their goals are essentially antithetical to Western life, that is a perhaps sobering point.