Bret Devereaux: "In the United States [during World War II], an air campaign expressly aimed at killing German civilians to compel surrender was politically unpalatable (there were fewer such compunctions against doing this to Japan, due in no small part to racism), so the theory the USAAF went with was aimed at production rather than morale, which had emerged in the then U.S. Army Air Corps during the 1930s. The idea, informally called ‘Industrial Web Theory,’ was that an enemy’s industrial capacity was a fairly fragile web which could be disrupted by striking key nodes and that these disruptions would cause military production – ammunition, weapons, fuel and all of the other necessary things for ground warfare – to come to a near-halt, depriving the enemy of the ability to field a modern army and thus forcing them to surrender. Doing this would require being able to accurately deliver bombs to smaller targets (factories and railyards, not cities) but the USAAF was confident that such accuracy was possible"
However, " the accuracy to enable pin-point targeting of industrial facilities simply wasn’t there. By way of example [...] in 1944 the allies attempted from May to November in a series of raids to destroy an oil plant in Leuna, Germany. The plant was 1.2 square miles in total size and yet 84% of all bombs missed. In the USAAF, the problem of accuracy led to a shift in tactics [...] Consequently, industrial damage was far less than was hoped. Instead of falling, German production continued to rise – indeed, it tripled – until territorial losses to the advancing Soviet and Allied armies finally curtailed production."
"[B]ombing did serve to stunt German production growth, but the strategic effect of disabling German industry to the point that the war couldn’t be continued was wildly, overwhelmingly out of reach. The opponent could, after all, react, dispersing and protecting industry, limiting the impact of bombing campaigns. Industrial bombing thus achieved something, but it is unclear if it achieved anything to be worth the tremendous investment in vast fleets of bombers necessary to do it."
"Industry bombing and industrial web theory was thus the framework the Air Force had going into both the Korean and Vietnam Wars. Both wars presented a major problem: the industry actually sustaining the war effort wasn’t in the combat zone and couldn’t be attacked due to political concerns. During the Korean War, North Korean forces were largely supplied by China and the USSR; attacking either might trigger a nuclear retaliation and so was rejected. "
"In Vietnam, the same problem complicated any effort at industrial bombing: the factories that supplied the North Vietnamese forces (both the regular PAVN and irregular NLF) were in China and especially the USSR. Moreover the population was not broadly dependent on centralized utilities (like electricity) which could be bombed."
"Nevertheless over the course of the operation the United States dropped some 643,000 tons of bombs on North Vietnam, a fraction of the even larger total used during the entire war (though the great majority of that larger total, around 8,000,000 tons, were dropped on targets outside of North Vietnam). The net effect on the industrial basis of the war effort was not significant. Meanwhile, Mark Clodfelter has argued (inter alia), in The Limits of Air Power (2006) that the campaign actually harmed US political objectives and helped North Vietnamese goals, securing North Vietnam’s firm support from both its populace and its international sponsors while at the same time dividing the American public and thus sapping support for the war. Once again – wait for it – being bombed hardened civilian will to resist."
"[T]he air campaign over Kuwait and Iraq in 1991 was clearly effective; Coalition forces achieved victory in the Gulf War far faster and at far less cost than had generally been anticipated. On the other hand, air operations in both the first Gulf War and then more than a decade later during the invasion of Iraq in 2003, it was not clear that any kind of strategic paralysis was achieved. The DoD’s own report, issued in 1993 (Cohen and Keaney, Gulf War Air Power Survey (1993)) noted first that only some 15% of strikes were against ‘strategic’ targets, while strikes against Iraqi ground forces consumed 56% of strikes"
"Despite effectively running out the entire list of strategic targets, Cohen and Keaney nevertheless conclude that strategic effects were broadly not achieved. Despite striking the Iraqi communications network with more than 580 strikes, “the Iraqi government had been able to continue launching Scuds” and “sufficient ‘connectivity’ persisted for Baghdad to order a withdrawal from the theater [Kuwait] that included some redeployments aimed at screening the retreat.” Consequently, “these attacks clearly fell short of fulling the ambitious hope” to “put enough pressure on the regime to bring about its overthrow and completely sever communications between Baghdad and their military forces.” Instead airpower continued to show its greatest impact through non-strategic effects: destroying or disorienting enemy ground forces in order to make the advance of friendly ground forces quicker and easier."
In summation, "bombing can have some effect on industrial production, but only in wars where that production matters and is available to be bombed; at the same time the impact of that industrial bombing is also likely to be sharply reduced by enemy efforts to shield industrial capacity from bombing and at the same time to prioritize military production with what industrial capacity remains."