War is too serious, and too expensive, to be left to the whim of chance, yet throughout history many governments have been willing to engage in war if it suited their interests as they perceived them, and many have also been dragged into wars when cooler calculations might have encouraged them to remain at peace. It was out of the need to raise the finance to conduct wars that the earliest systems for collecting public finance developed.

The practice of taxing the population to pay for war has a long history. In early nomadic societies, wars could be fought with little expense other than time and casualties. Nomadic horsemen engaged in war as an extension of their normal activities as herdsmen. If successful, the warriors plundered the defeated, who were either killed, sold, or scattered. With more-settled agricultural societies, wars could be fought between planting and harvest, the armies living off of the land or the pay of the king. In the feudal system each man had an obligation to fight if required by the lord of the manor, to whom the vassal owed his livelihood. Weapons were often the personal possessions of the warriors and were fashioned by themselves, their forebears, or craftsmen. As weapons improved in quality and ingenuity, special efforts to produce them had to be made—for which their producers were paid out of public funds, as were the soldiers to whom they were distributed. These expenses necessitated the collection of special funds, and thus the government turned to levies on the population to provide the resources.

Where taxation alone was not sufficient to pay for a war, the king could resort to selling relief from feudal obligations (usually to prosperous cities), and to borrowing from rich individuals (who risked confiscation if they refused and not being paid back if they agreed). Most political crises in European history up to the 19th century arose from disputes over public finance, usually to pay for wars. The English Civil Wars of 1642–51 were a typical example of a bitter dispute between king and parliament over which had the powers of taxation.

By the time of the French Revolution in 1789, warfare had ceased to be a localized affair with a few thousand soldiers engaged in a single decisive battle. Warfare had become a massive undertaking, often lasting months and years and involving armies of hundreds of thousands. The expense of war reached levels unheard of previously. The Royal Navy, for instance, employed 200,000 men in the 1790s alone. Out of the need to find new sources of revenue for the long war between Britain and France from 1793 to 1815, the British government introduced a temporary income tax to be levied on all persons earning above a high minimum income. The advantages of the system soon became evident, and income taxes were widely adopted as permanent sources of government revenue.

The British government also discovered another source of revenue, the national debt. Whereas previous borrowings by monarchs were a great risk to the lender, under the national debt scheme the government agreed to guarantee regular payment of interest to all persons who lent to it, either in perpetuity or for a fixed term. Holders of government bonds were also permitted to sell them, passing the right to the guaranteed income to the buyer. Again, the system was so successful that it was soon copied by other governments, not all of them as scrupulous in their repayments as they promised. War bonds featured strongly in the two world wars, and it was regarded as patriotic to use personal savings to purchase them—though most of the borrowing came from institutions.

The new sources of war finance enabled the increased expense of war to be met—and, in the opinion of some economists, made it more likely that a government would embark on a war for less than good reason. If war had to be financed out of the current consumption of the population, natural limits would be set on war being undertaken lightly, but borrowing removed these limits. Though the population would be saddled with interest payments for decades to come, this cost was small and of long duration compared to the immediate cut in living standards that would have to be made to pay for a war in full.

A major modern war can divert from 40 to 60 percent of a country’s GDP, and one object of war finance is to release within the economy the resources needed for the war effort without causing inflation. If the government merely prints money to pay for the resources it requires, it will bid up prices in competition with civilians. The alternative is to reduce civilian consumption by imposing taxes at levels sufficient to force consumers to forego bidding for goods and services. The income from taxes can then be applied by the government to bid for the resources released by its program.

Taxation acts both to raise necessary finance and simultaneously to reduce aggregate demand, which releases the resources needed for the war effort. The war effort represents a substantial expansion of production, for which producers receive wages and profits. When these same producers attempt to spend their incomes, they face a diminished quantity of civilian goods available for purchase. They must either face rapidly rising prices (caused by excess money chasing insufficient goods), or they must restrain—or be restrained—from spending. A war economy therefore imposes higher taxes on wages and profits to reduce demand. War bonds and taxes provide finance for the war effort and reduce demand for civilian goods and services. To conduct a major war without such an austerity program risks inflation.

If inflation is a risk during a war, recession is another risk at the end of it. The massive expansion in production to provide resources for the war effort, if suddenly contracted by the cancellation of all defense contracts, throws large numbers of people out of work. The unemployed reduce their consumer spending, causing further cuts in aggregate demand, which throws yet more people out of work.

World War I was followed by recession. Because much of the war damage along the Western Front was confined to the vast, static battlefields across France, where the destruction was mainly human and the cost was mainly in war materials, there was no need for a massive reconstruction program. Also, the damage on the Eastern Front was swept behind the newly formed Soviet state, which for ideological reasons eschewed capitalist reconstruction. After the war factories closed down, removing a flow of wages and profits into the economy, the demobilization of troops put surplus labour into an economy that was already in recession.

Recession was averted at the end of World War II by reconstruction of the cities and economies of western Europe and Japan. Reconstruction rapidly transformed the war economies into mass consumer economies supported by the pent-up demand that had been frustrated by the lack of civilian goods and by high taxes during the war. In Europe’s case there was a transfer of capital from the United States through the Marshall Plan. As the war economies were dismantled, economic growth surged, and those countries that did best economically were those that dismantled their highly regulated, government-controlled war economies quickest (West Germany, for example). Those countries that were least successful in dismantling their regulated economies were the slowest to recover. Among these were Britain, which increased state intervention from 1946 to 1951, and the Soviet-controlled economies of eastern Europe, which went even further down the road of government-managed economies.

Gavin Kennedy, Defence Economics (1983), is a general survey written for the nonspecialist and providing information on a broad spectrum of questions of military appropriations and expenditures. Historical studies include J.M. Winter (ed.), War and Economic Development (1975), addressing the economic consequences of war on the preindustrial economies of Europe; Gautam Sen, The Military Origins of Industrialization and International Trade Rivalry (1983), exploring the influence of military technology on the industrial development of Europe; and Emile Benoit, Defense and Economic Growth in Developing Countries (1973), challenging the assumption that defense spending is incompatible with economic growth and attempting to show that defense spending has actually assisted economic development in some Third World countries. Saadet Deger and Robert West (eds.), Defence, Security, and Development (1987), is a collection of articles by scholars from several countries who criticize Benoit’s method and conclusions and provide a more complex assessment of the connection between economic growth and national security. A detailed study of governmental defense planning in poorer economies is presented in Stephanie G. Neuman (ed.), Defense Planning in Less-Industrialized States: The Middle East and South Asia (1984). For a view that defense spending inhibits economic performance, based on international comparative data and statistical analysis, see Robert W. Degrasse, Jr., Military Expansion, Economic Decline: The Impact of Military Spending on U.S. Economic Performance, expanded ed. (1983). Christian Schmidt (ed.), The Economics of Military Expenditures: Military Expenditures, Economic Growth, and Fluctuations (1987), collects papers by most of the world’s leading specialists in defense economics, providing a rich agenda in the contribution of economic analysis to defense dilemmas.

A rare comparative study of defense industries in both capitalist and communist economies of such countries as the United States, the Soviet Union, France, Germany, Sweden, Czechoslovakia, Italy, China, Israel, the United Kingdom, and some representatives of the Third World is provided in Nicole Ball and Milton Leitenberg (eds.), The Structure of the Defense Industry: An International Survey (1983).