If a 10-megaton weapon made a direct hit on a target area, a large fraction of the population of that target area would be killed, unless blast shelters were available. Also, the destruction of productive capacity would be essentially total. If fallout shelter were available for the entire population, and there were essentially no primary blast shelter available, the population curves may give a rough approximation to the casualties that would result if the indicated number of target areas were attacked.

These, of course, are urban and industrial areas, and the number given does not include any allowance for attacks on strategic forces per se.

Perhaps, in order to clarify the situation with respect to the degree of blast protection involved here, I should say that the peak overpressure at the edge of a target area would be in the range of 2 to 7 p.s.i. if a 10-megaton weapon were detonated at the center of the target area.

Mr. HOLIFIELD. At what distance?

Mr. WINTER. The target areas used in this calculation are actually square areas, 20 kilometers (12.4 miles) on a side. Thus the points on the perimeter of the area would be between 6.2 and 8.8 miles from the center of the square. For a surface burst, the peak overpressure at the shorter distance would be about 3 p.s.i. and at the longer about 5; the results would of course be different for airbursts at various altitudes. The physical damage produced at these overpressure levels would be severe. However, good fallout shelters would provide blast protection adequate for this range of overpressures, as you have pointed out, Mr. Chairman.

The "rough approximation" that these curves provide to the casualty levels when the indicated number of areas are hit is probably very rough indeed.

These curves cannot safely be used for the purpose of estimating casualties and damage from any particular attack, but they are very useful for getting a picture of the range of situations that may arise with respect to the balance between surviving resources and population.

EFFECTS OF DIFFERENT TARGET SYSTEMS ON INDUSTRY

The level of destruction of any particular resource when a given number of target areas are hit obviously depends on which target areas are on the list. Figures W-1 and W-2 illustrate the different situations that arise with respect to the balance between population and survival industry. Survival industry is a broad industrial category including the industries that are important in meeting the basic

needs of the population-for example-food processing industries, medicines and medical supplies, apparel, fuels, and various industries that produce goods needed in repair of basic utilities. In Figure W-1, the concentrations are shown for the case where the areas are ranked according to population. The population curve shows, for example, that the 120 largest target areas in terms of population contain 40 percent of the country's population. The survival industry curve shows that those same 120 areas contain about 55 percent of the survival industry, in spite of the fact that the 120 areas were chosen for their high population rather than the amount of survival industry they contained. This illustrates the general tendency for industrial activity to be more concentrated geographically than the population. Figure W-2 shows the situation when survival industry, rather than population, is singled out as the target system. As might be expected, the result is that the amount of survival industry included in any given number of areas substantially exceeds the amount shown on the previous chart, while the percentage of the population is smaller. I want to relate this second chart to the conclusion I developed earlier, that the problem of supporting the surviving population is unlikely to be serious if the proportion between surviving economic capacity and population does not fall below about half its prewar value. The case where survival industry is specifically targeted is the worst case from the point of view of reducing that ratiounless, of course, the enemy also attempts specifically to avoid causing population casualties, which would be welcome. Examining the ratio between the proportions of the two categories outside any given number of target areas, we find that the ratio is about 0.75 at 40 areas, and at the right-hand side of the chart the ratio seems to be stabilizing at around 0.40. Since, as was noted earlier, the percentage of most industries required to support 1929 consumption standards is well under 40, and since 1929 standards are a long way from threatening the survival of the population, it appears that enough capacity would survive to support the surviving population even in the worst possible case. It should be noted, however, that survival industry is an aggregate, and some industries would suffer destruction in greater proportion than the aggregate. However, surviving inventories of necessities should be more than sufficient to support the population until these severe bottlenecks can be alleviated.

CONCENTRATION OF MILITARY SUPPORT INDUSTRY

The next two curves show the relative concentrations of population and of a group of industries needed in recovery and support of military forces. (See figs. W-3 and W-4, pp. 320 and 321.)

The group contains mainly heavy industry-the primary metals, machinery, industrial chemicals, aircraft, and so on. We find that this group is more concentrated than survival industry. In particular, when target areas are ranked according to the amount of recovery and military support industry they contain, it turns out that something like two-thirds of the total is in the first hundred areas. Support of military forces would be very difficult relative to the problems of survival, let alone in absolute terms. Also, this result indicates that recovery might get off to a slow start as a result of relatively heavier destruction in the industries required for the production of new capacity. This is in line with the conclusions of earlier studies.

As a last comment on the concentration of resources, I want to mention the fact that severe bottlenecks can easily be produced in certain industries if the enemy chooses to attempt this. A good illustration is petroleum refining. (See fig. W-5 on opposite page.) Figure W-5 shows that concentration of capacity in this industry is about the same as the concentration of population, when the areas are ranked by population. A dramatic change occurs when petroleum refining is singled out. (See fig. W-6, p. 323.)

Over 90 percent of the industry is in about 100 areas, and 121⁄2 percent of the population. Given the extent of our dependence on petroleum for tractor fuel and transportation, this is disturbing. However, the significance of this sort of result can be exaggerated. A heavy attack on a specific, concentrated target system will generally result in significantly less total destruction than one aimed at the population or the economy in general. If imports are possible, the recovery problem may not be as serious as in the more general attack. Also, the apparent importance of these severe bottlenecks tends to diminish when they are examined closely, and the possibility that they can be avoided by modest preparations often seems more likely. Both of these statements apply in the case of petroleum. It should also be noted that, in order to destroy a very large proportion of our petroleum refining capacity with high confidence, the enemy would certainly have to assign more than one weapon per target area.

RESTORATION OF PREWAR GROSS NATIONAL PRODUCT

I now want to examine, very briefly, the question of how long it might take to restore gross national product to its prewar level after a thermonuclear war, assuming now that the reorganization problem can be solved-that is, that the economy can be restored at least to the point where it is viable. (Needless to say, the question of the rate of recuperation is not reached unless there is reason to think that a cumulative decline can be avoided.) I also assume low levels of Government expenditure. Rather than making specific assumptions on damage levels, I consider a situation where the full population survives and half the economy's capacity is destroyed. This is clearly unrealistic, but the relative balance between surviving industry and population is on the pessimistic side here, and the results of the following calculations in per capita terms depend only on the relative balance. This emphasis on the relative balance can be quite misleading when destruction levels are high, but not nearly so misleading in