Air power enthusiasts, of which Rummy is one, always put great faith in the notion that air power can win wars virtually alone, or something close to that.
No one disputes the effectiveness of tactical air power used in support of infantry operations. The effectiveness of strategic air power used against economic and infrastructure targets is very much a disputed issue. And not just by the inter-service rivals of the Air Force in the other services.
In the Vietnam War, Lyndon Johnson began a massive strategic bombing campaign in 1965 which was called Rolling Thunder. In 1972, the DRV (North Vietnamese) used conventional forces in a drive into South Vietnam, making themselves vulnerable to the full force of the US' tactical air power. Late in 1972, Richard Nixon ordered a massive bombing campaign, popularly known as the Christmas Bombing, aimed (he and his apologists later claimed) at winning better peace terms in the Paris negotiations. There is strong evidence that he actually intended to carry on the war much longer than he did, but the domestic and international reaction was so negative he had to back off.
In his The Hidden History of the Vietnam War (1995), John Prados discusses the work of Mark Clodfelter on US bombing during the Vietnam War. Prados writes:
Clodfelter ... argues that Rolling Thunder was limited by what he terms Lyndon Johnson's "negative objectives" - preventing a third world war and keeping both domestic and international opinion focused elsewhere than Vietnam. The 1972 bombing called Linebacker is seen as effective because Richard Nixon supposedly did not have such negative objectives behind his air campaign (and because the North Vietnamese had shifted to a pattern of conventional ground operations). This particular argument is something of an intellectual construct. For LBJ, bombing North Vietnam in fact encouraged Soviet and Chinese participation, both to replace assets destroyed by Rolling Thunder and to help man the DRV's air defenses. It was constantly at the back of the president's mind that if he escalated too far, he would bring the Communist powers in openly for a larger war; but this is scarcely the same as pursuing a "negative objective." As for Richard Nixon, the 1972 strategy most assuredly did have equivalent negative objectives - avoiding domestic political backlash in the midst of an election campaign - and part of the reason for his selection of air power as the instrument of intervention was precisely because it was seen as the least costly option in political terms. Again, the reason for rhe relative success of bombing in 1972 comes back to the differences in North Vietnamese military practice, not to an improvement in the nature of air war strategy.
A great deal of the criticismof the US military effort in Vietnam has focused on the restrictions placed on the bombing campaign. A more aggressive bombing campaign, it is argued, could have gone a long way toward defeating North Vietnam and achieving the aim of preserving an independent, non-Communist South Vietnam.
Some of that criticism has to do with the theory employed by Robert McNamara and the civilians in the Pentagon that saw bombing primarily as a means of diplomatic communication. It seems to me that there's a valid point to this kind of criticism. That doesn't mean that there is no political/diplomatic point to bombing, though, just that the particular theory of aerial warfare they were applying failed in its application in the Vietnam War.
Much more familiar is the criticism that Johnson in particular interfered far too much with the selection of particular targets for bombing and restricting bombing of others. The idea in that kind of critique is generally that if the military had been allowed to bomb wherever they thought appropriate in Vietnam, Laos and Cambodia, we could have "won" the war.
Not likely. Prados writes:
Despite all the arguments about target lists and strategy, the way the air war ended reveals most dramatically its true nature as a diplomatic tool. For the fact is that Lyndon Johnson simply called off the air war, just as he had ordered bombing pauses a half-dozen times before, to create an opening for diplomacy. His order came on March 31, 1968, when he simultaneously withdrew from that year's presidential election. Disgruntled generals and admirals have never forgiven the president his decision, but they seem to have forgotten the purpose of the air war, not to mention the president's prerogative to make the decision that he did.
And for those who think that the air war was too soft because the sissy civilians wanted to go easy on the commies, Prados has this reminder. Here he's looking at the bombing from 1965 to 1968, when Johnson called a bombing half:
The weight of ordnance expended during this "restricted" air campaign (not counting the 1972 bombing, which was even more destructive) was about a third greater than the total tonnage of bombs dropped in the entire Pacific Theater in World War II, including both the strategic bombing of Japan and the atomic bombs dropped on Hiroshima and Nagasaki. There must have been something wrong with the air war strategy other than the restrictions placed upon it. Left to another war in another time and place was the air enthusiasts' dream of proving their arm the sole decisive weapon of warfare.