Defense Spending for Protracted Conflict: Lessons from the Napoleonic Wars
Defense Spending for Protracted Conflict: Lessons from the Napoleonic Wars
The MOC
By Luke Widenhouse
May 28, 2025
The major challenge facing the United States in a great power war over the Republic of China (Taiwan) would be the very real possibility that such a war would become a protracted one. Both the United States and the People’s Republic of China (China) place immense strategic value on Taiwan. In a war over the island’s freedom, both sides are likely to continue fighting until they either triumph or do not have the personnel or materiel to continue sustaining the war. Some analysts have offered up Great Britain’s experience during the French Revolutionary and Napoleonic Wars (1793-1815) as a useful basis for formulating a strategy to counter Chinese aggression, and hopefully deter a war from breaking out in the first place. British wartime spending also provides a number of lessons that the U.S. would do well to learn from.
In thinking about protracted conflict with China, the United States faces the challenge of having to build a budget and force structure for a long-term threat. Publicly available wargames indicate that the United States would likely “win” a war with China over Taiwan taking place in the 2026–2028 timeframe, though victory would come at an incredible loss in blood and treasure. Moreover, like the early battles of the Napoleonic Wars, such a conflict would not settle the fundamental strategic rivalry between the U.S. and China, and likely just be the first in a series of conflicts between the two great powers. Understanding how various aspects of public financing contribute to overall military effectiveness is therefore crucial.
A simple model was developed by Air Force Lieutenant Colonel Gregory G. Hildebrandt in an August, 1980 RAND Corporation publication to relate a country’s military spending ME to its force potential MF, given by the equation:
MF=ME+rK+K-IN-IR
Where rK is the interest charge on military capital, K is the capital loss, IN is net investment, and IR is research, development, test, and evaluation (RDT&E). Applying these equations to the British situation throughout its 22 years of war with France helps to better illustrate how various interacting factors in British wartime financing contributed to its ultimate victory, with low interest rates being especially important.
The chart below shows Britain’s military spending levels over the course of the wars from 1793 to 1815, adjusted for inflation. It should be noted that the conflict with France was not confined to a single war. Peace treaties were signed with France, only to be broken, and alliances shifted over time as successive anti-French coalitions were defeated and reformed along new lines. Spending therefore adjusted itself in line with the level of danger that Britain felt that it faced from France. The United States would likely find itself in a similar situation in a protracted war with China, with some periods seeing higher levels of military spending than others. A version of this trend can already be illustrated during the War on Terror, when overall military spending rose substantially from 2001 to 2018, while also seeing a large confined increase during the surge of troops to both Iraq and Afghanistan.
In 1793, Britain’s gross military spending amounted to £1.28 billion. By 1815, this had increased to £4.05 billion. The interest charge on capital was maintained at roughly three percent throughout this entire period. In obtaining an overall estimate of military force potential, it is necessary to exclude K and IR from the calculations, the former because of inflation, and the latter because of the lack of available data. Thus, Britain’s military force potential in the Napoleonic Wars can be calculated as the sum of overall military spending and the interest charge on capital, minus net investment. While IN would ordinarily be calculated as new investment at some point t minus the depreciated value of investment made before t that still remains in the inventory, or:
P1,bN1,t-1K1,t,
it is easier with historical data to simply calculate IN as the overall value of “new” investment, adjusted for inflation. In this case, Britain’s “net” increase in spending amounted to £2.8 billion. Thus, 4.04+1.2-2.8=2.44, representing a military force potential that grew at fairly sustainable levels over the course of the war.
A large amount of military spending during the war was covered by borrowing, with taxation (Britain introduced its first income tax in direct response to the need to raise revenue for the war), and changes in monetary policy, most notably the abandonment of the gold standard in 1797. From 1793 to 1798, nearly ninety percent of all wartime spending was covered by borrowing. In essence, the conflict with France demanded that spending be sustained at significantly higher deficits and over a longer period than previous eighteenth century wars. Britain’s credibility as a debtor was fundamental to its ability to maintain these deficits. Financiers trusted that the British government would eventually repay its loans in full. By contrast, the uncertainty brought on by the French Revolution led to a general distrust of the French government among potential financial backers, despite revolutionaries’ promises that France’s debts would be paid off.
The equations show that a significant portion of force potential is related to its ability to maintain sustainable interest rates on capital charges. This may then be the most important lesson for the U.S. to take away from the Napoleonic Wars. The U.S. currently runs deficits to finance its public spending, and, as in all wars, would have to surge spending in order to maintain a proper level of military capability.
Of course, British wartime financing was not the only important contributor to its success during the Napoleonic Wars. Equally important was how it actually spent money. Here, additional lessons should be learned by the United States, and applied to the modern day. Britain faced shortfalls in military strength when compared to France. As noted by Paul Kennedy in his book “The Rise and Fall of the Great Powers,” Britain’s population was 16 million, significantly smaller than France’s population of 30 million. Its land army also remained significantly smaller than France, peaking at just around 250,000 soldiers in 1813. By contrast, Napoleon’s Grande Armée was able to muster over a million men that same year. However, Britain did not fight alone. Westminster was able to offset its landpower disadvantage by paying subsidies to its allies, particularly Russia and Austria, who in turn were able to field continental land armies of considerable strength.
While Britain did not maintain a particularly large army, the Royal Navy rose to become inarguably the best in the world at the time. Britain’s dependence on trade and overseas commerce made sea control critical to its survival. Vice Admiral Horatio Nelson’s defeat of a combined Franco-Spanish fleet off Cape Trafalgar in 1805 solidified Britain’s command of the seas, but the victory was secured because of Britain’s dedication to fielding a large and capable navy with well-trained crews and experienced officers.
Modern sea control involves both investment into surface warships and submarines, but also in air, space, and cyber forces; in other words, the services responsible for operating in and defending the areas critical for global commerce, transportation, and power projection, but where humans do not actually live. The Army’s traditional maneuver elements may then need to accept some diminished levels of spending in order to fund more critical capability areas. The armies of allied nations in the Indo-Pacific could offset the corresponding disadvantage in land capabilities. Although the U.S. Army is much larger than the armies of its Indo-Pacific partners, the size of U.S. Army Pacific is relatively small, with around 106,000 soldiers. By contrast, the Japan Ground Self-Defense Force is composed of 150,700 active soldiers, the Republic of Korea Army 365,000 soldiers, and the Philippine Army 150,000 soldiers. These numbers do not include reservists who would likely be activated in the event of a major war. While the U.S. Army would certainly grow in size during a war, the protracted character of the conflict makes the sustainability of conscription questionable at best. It is also important to consider the cost of transporting and sustaining a large group of soldiers in the Indo-Pacific in a highly contested maritime environment.
Ultimately, the United States faces the challenge of having to make hard choices when it comes to which capabilities it can invest in during a protracted great power conflict in the Indo-Pacific. Naval, air, and space capabilities are essential to the United States’s ability to win such a war. Like Great Britain during its long conflict with Revolutionary and Napoleonic France, a tradeoff in landpower, offset by allies, may be the most effective means of financing a long fight.
Luke Widenhouse is a research assistant at the Yorktown Institute and a graduate of St. John’s College in Annapolis, MD.
The views expressed in this piece are the sole opinions of the author and do not necessarily reflect those of the Center for Maritime Strategy or other institutions listed.
By Luke Widenhouse
The major challenge facing the United States in a great power war over the Republic of China (Taiwan) would be the very real possibility that such a war would become a protracted one. Both the United States and the People’s Republic of China (China) place immense strategic value on Taiwan. In a war over the island’s freedom, both sides are likely to continue fighting until they either triumph or do not have the personnel or materiel to continue sustaining the war. Some analysts have offered up Great Britain’s experience during the French Revolutionary and Napoleonic Wars (1793-1815) as a useful basis for formulating a strategy to counter Chinese aggression, and hopefully deter a war from breaking out in the first place. British wartime spending also provides a number of lessons that the U.S. would do well to learn from.
In thinking about protracted conflict with China, the United States faces the challenge of having to build a budget and force structure for a long-term threat. Publicly available wargames indicate that the United States would likely “win” a war with China over Taiwan taking place in the 2026–2028 timeframe, though victory would come at an incredible loss in blood and treasure. Moreover, like the early battles of the Napoleonic Wars, such a conflict would not settle the fundamental strategic rivalry between the U.S. and China, and likely just be the first in a series of conflicts between the two great powers. Understanding how various aspects of public financing contribute to overall military effectiveness is therefore crucial.
A simple model was developed by Air Force Lieutenant Colonel Gregory G. Hildebrandt in an August, 1980 RAND Corporation publication to relate a country’s military spending ME to its force potential MF, given by the equation:
MF=ME+rK+K-IN-IR
Where rK is the interest charge on military capital, K is the capital loss, IN is net investment, and IR is research, development, test, and evaluation (RDT&E). Applying these equations to the British situation throughout its 22 years of war with France helps to better illustrate how various interacting factors in British wartime financing contributed to its ultimate victory, with low interest rates being especially important.
The chart below shows Britain’s military spending levels over the course of the wars from 1793 to 1815, adjusted for inflation. It should be noted that the conflict with France was not confined to a single war. Peace treaties were signed with France, only to be broken, and alliances shifted over time as successive anti-French coalitions were defeated and reformed along new lines. Spending therefore adjusted itself in line with the level of danger that Britain felt that it faced from France. The United States would likely find itself in a similar situation in a protracted war with China, with some periods seeing higher levels of military spending than others. A version of this trend can already be illustrated during the War on Terror, when overall military spending rose substantially from 2001 to 2018, while also seeing a large confined increase during the surge of troops to both Iraq and Afghanistan.
In 1793, Britain’s gross military spending amounted to £1.28 billion. By 1815, this had increased to £4.05 billion. The interest charge on capital was maintained at roughly three percent throughout this entire period. In obtaining an overall estimate of military force potential, it is necessary to exclude K and IR from the calculations, the former because of inflation, and the latter because of the lack of available data. Thus, Britain’s military force potential in the Napoleonic Wars can be calculated as the sum of overall military spending and the interest charge on capital, minus net investment. While IN would ordinarily be calculated as new investment at some point t minus the depreciated value of investment made before t that still remains in the inventory, or:
P1,bN1,t-1K1,t,
it is easier with historical data to simply calculate IN as the overall value of “new” investment, adjusted for inflation. In this case, Britain’s “net” increase in spending amounted to £2.8 billion. Thus, 4.04+1.2-2.8=2.44, representing a military force potential that grew at fairly sustainable levels over the course of the war.
A large amount of military spending during the war was covered by borrowing, with taxation (Britain introduced its first income tax in direct response to the need to raise revenue for the war), and changes in monetary policy, most notably the abandonment of the gold standard in 1797. From 1793 to 1798, nearly ninety percent of all wartime spending was covered by borrowing. In essence, the conflict with France demanded that spending be sustained at significantly higher deficits and over a longer period than previous eighteenth century wars. Britain’s credibility as a debtor was fundamental to its ability to maintain these deficits. Financiers trusted that the British government would eventually repay its loans in full. By contrast, the uncertainty brought on by the French Revolution led to a general distrust of the French government among potential financial backers, despite revolutionaries’ promises that France’s debts would be paid off.
The equations show that a significant portion of force potential is related to its ability to maintain sustainable interest rates on capital charges. This may then be the most important lesson for the U.S. to take away from the Napoleonic Wars. The U.S. currently runs deficits to finance its public spending, and, as in all wars, would have to surge spending in order to maintain a proper level of military capability.
Of course, British wartime financing was not the only important contributor to its success during the Napoleonic Wars. Equally important was how it actually spent money. Here, additional lessons should be learned by the United States, and applied to the modern day. Britain faced shortfalls in military strength when compared to France. As noted by Paul Kennedy in his book “The Rise and Fall of the Great Powers,” Britain’s population was 16 million, significantly smaller than France’s population of 30 million. Its land army also remained significantly smaller than France, peaking at just around 250,000 soldiers in 1813. By contrast, Napoleon’s Grande Armée was able to muster over a million men that same year. However, Britain did not fight alone. Westminster was able to offset its landpower disadvantage by paying subsidies to its allies, particularly Russia and Austria, who in turn were able to field continental land armies of considerable strength.
While Britain did not maintain a particularly large army, the Royal Navy rose to become inarguably the best in the world at the time. Britain’s dependence on trade and overseas commerce made sea control critical to its survival. Vice Admiral Horatio Nelson’s defeat of a combined Franco-Spanish fleet off Cape Trafalgar in 1805 solidified Britain’s command of the seas, but the victory was secured because of Britain’s dedication to fielding a large and capable navy with well-trained crews and experienced officers.
Modern sea control involves both investment into surface warships and submarines, but also in air, space, and cyber forces; in other words, the services responsible for operating in and defending the areas critical for global commerce, transportation, and power projection, but where humans do not actually live. The Army’s traditional maneuver elements may then need to accept some diminished levels of spending in order to fund more critical capability areas. The armies of allied nations in the Indo-Pacific could offset the corresponding disadvantage in land capabilities. Although the U.S. Army is much larger than the armies of its Indo-Pacific partners, the size of U.S. Army Pacific is relatively small, with around 106,000 soldiers. By contrast, the Japan Ground Self-Defense Force is composed of 150,700 active soldiers, the Republic of Korea Army 365,000 soldiers, and the Philippine Army 150,000 soldiers. These numbers do not include reservists who would likely be activated in the event of a major war. While the U.S. Army would certainly grow in size during a war, the protracted character of the conflict makes the sustainability of conscription questionable at best. It is also important to consider the cost of transporting and sustaining a large group of soldiers in the Indo-Pacific in a highly contested maritime environment.
Ultimately, the United States faces the challenge of having to make hard choices when it comes to which capabilities it can invest in during a protracted great power conflict in the Indo-Pacific. Naval, air, and space capabilities are essential to the United States’s ability to win such a war. Like Great Britain during its long conflict with Revolutionary and Napoleonic France, a tradeoff in landpower, offset by allies, may be the most effective means of financing a long fight.
The views expressed in this piece are the sole opinions of the author and do not necessarily reflect those of the Center for Maritime Strategy or other institutions listed.