Military manpower requirements, whether for active or reserve service in the armed forces or for defence research and development, absorb a considerable number of educated people who would otherwise be able to pursue more constructive activities. Considerable managerial talent and technical skill is utilized by the military branches, and in many cases military personnel go through long and extremely arduous courses of training in special educational establishments. The increasing sophistication of weapons means that whatever the percentage of a national budget which goes towards military expenditure, the corresponding percentage in terms of the use of professional scientific manpower will be higher. It is usual to find that in countries with developed military industries, the proportion of the labour force in the engineering industry which is absorbed in the production of military equipment is far greater than the percentage of GNP which goes to military expenditure, and that the percentage of all qualified scientists and engineers employed on military research and development is even higher.
There has been only a slow rise in the numbers of the world's armed forces. Both since 1914 and since 1960, the numbers appear to have increased at 2.0-2.5% a year (this is about one-third as fast as the increase in military expenditure). However, in a number of countries the armed forces have been employing an increasing number of civilians to do work previously done by servicemen. The total in 1980, including civilian support staff, was estimated at 39 million. Virtually all the increase in military manpower occurred in the developing countries whose share of the overall total for the world's armed forces is now about 60%, in contrast to a less than 10% share in military expenditure. Over recent decades the numbers in their armed forces have risen significantly. It has been estimated that about 10 million people around the world are employed by arms manufacturers. Probably at least a quarter of the world total of scientists and engineers engaged in research and development are in fact employed on military work. Military research and development probably absorbs nearly one million scientists, engineers and their support staffs of technicians and others.