Throughout history, wars have had many causes, from the desire to control oil reserves to the need for power, but people tend to forget that wars are not free. Conversely, the cost of fighting is quite high – especially when it involves multiple fronts and requires global travel and coordination.
From guerrilla warfare in the jungles of Vietnam or East Africa to military crime in the deserts of Europe and the Middle East, these are the most costly wars in history – not just monetary.
1. World War II
Cost: $4.7 trillion* (2021)
Location: Worldwide
Duration: 1939-1945
World War II began because of a man's need for power and his desire to wipe out an entire race and anyone who stood in his way through genocide. For the second time in 25 years, the world has united against Germany. This time, the war paid a greater price in every way than any previous war, and so did almost all subsequent wars.
Adjusted to today, the war that redefined the layout of World War II may not be the most expensive war in history, but it is very close, and with an estimated 85 million casualties, it is the deadliest war to date. The collateral cost of Germany's attempts to dominate the world is more than $33 billion in reparations to civilians, Holocaust survivors and the State of Israel.
2. The War of 1812
Cost: $2.8 trillion* (2021)
Location: United States
Duration: 1812-1815
As Britain was busy with the Napoleonic Wars in Europe, the United States hoped to take advantage of the situation by extending its territory northward to British North America. In other words, the United States wants to invade what is now Canada. The war ended in 1815, but before British troops could march to Washington and set the White House on fire.
In today's money, the war of 1812 cost nearly $3 trillion, and the 3 years of fighting shows little,if any, that the United States spent about 20 years recovering beyond its massive debt.
3. Cold War
Cost: $10 trillion*
Location: Worldwide
Duration: 1947-1991
The Cold War was by far the most expensive war for humanity, and ironically, no shots were fired between the two countries that made headlines on each side of the "battlefield." The war began as a contest between Russia and the United States after World War II — a power struggle — and ended when the Soviet Union collapsed in 1991.
The $10 trillion that entered the Cold War consisted mainly of the cost of a nuclear arms race between the two superpowers — for which the United States spent $5.8 trillion.
4. The Six-Day War
Cost: $1.12 billion*
Location: Israel
Duration: June 5, 1967 - June 10, 1967
For six days in June 1967, the State of Israel was attacked (to a large extent) by all five of its surrounding neighbors and iraq. Despite the Israeli army's 2.5-to-1 lead, they managed to repel the invaders and win the war.
In less than a week of fighting, more than $1 billion was spent, but it was a small price for Israel, which ended up getting in trouble with the priceless commodity peninsula of the Golan Heights, the West Bank, gaza strip, East Jerusalem and the Sinai Peninsula, which was returned to Egypt after a peace treaty with Israel.
5. American Civil War
Cost: $91 billion* (2021)
Location: United States
Duration: 1861-1865
The American Revolutionary War is considered by many to be the most important war on American soil, however, others attribute this honor to the American Civil War, which took place between the Confederation and the Allies and ended as a result, becoming slavery in the United States.
The Allies spent only $23 billion (2021), while the Alliance spent $68 billion (2021). To pay for the war, the U.S. government printed paper money (U.S. dollars) for the first time and sold about a billion dollars in bonds.
6. Civil War in Nigeria
Cost: $1-10 billion*
Location: Nigeria
Duration: 1967-1970
In 1967, a few years after Nigeria was decolonized by the British, the Republic of Bifra declared its independence from the rest of the country, and needless to say, the Nigerian government was not too happy, and a civil war broke out for most of the 3 years.
The cost of Bifra's failed 3-year attempt to independence is estimated to be between $1 billion and $10 billion, most of which is due to the Nigerian government from the United Kingdom, the United Nations and the Soviet Union.
7. Bosnian war
Cost: $250 billion*
Location: Bosnia
Duration: 1992-1995
After the dissolution of Yugoslavia in the early 1990s, the Bosnian people reached an impasse. The country split in two, with Croatia supporting Bosnia and Serbia supporting those opposed to the new nation-state. The ensuing war was a brutal one. Genocide and destruction have overwhelmed the country.
In total, nearly a quarter of the trillion dollars were invested in the Bosnian war. If we only count the damage done to Sarajevo, the Bosnian capital — about $18.5 billion — we will pay a greater price than many other wars in history.
8. The Russian Civil War
Cost: $35 billion* (adjusted for 2021)
Location: Russia
Duration: 1917-1922
In February 1917, a revolution in Russia witnessed the end of the Russian monarchy, which had been the ruling force in the world's largest country for more than 1,000 years, and established a new republic, the Russian Republic, as the temporary ruling force.
By October 1917, the New Republic had been overthrown and Russia was plunged into a bloody civil war that lasted most of the five years, culminating in the takeover of the Red Army and the formation of the Soviet Union. The 50 billion rubles ($650 million*) label of the Civil War may not seem like much, but today it equates to about $35 billion.
9. Korean War
Cost: $341 billion (2011)
Location: South Korea
Duration: 1950-1953
The escalation and ensuing wars in South Korea are not well known among people outside south Korea and the United States. It began with North Korea's invasion of South Korea in 1950 and ended with an armistice in 1953 (no formal peace treaty has yet been signed between the two countries), and the border between the two countries almost coincided with the beginning of the war.
At the end of the Korean War, the cost of the three-year battle totaled nearly $30 billion ($341 billion, 2011), but the real cost was more than 3 million lives lost, including about 1.2 million civilian war casualties.
10. Second Sudanese Civil War
Cost: $88.7 billion*
Location: Sudan
Duration: 1983-2005
Little is known about the civil war that has disrupted Sudan's life since 1955, for about a dozen years. The effects of what happened during the second Sudanese civil war — the most expensive and deadly conflict — remain. Felt it today.
When the Sudan People's Liberation Army (SPLA) stood up against Sudan's central government's push for territorial expansion, the imposition of Sharia law, and the country's freedom from all faiths, a 22-year civil war broke out estimated at $88.7 billion, ending with the SPLA helping South Sudan gain independence.
11. The War on Terror
Cost: $8 trillion*
Location: Worldwide
Duration: 2001 to present
In response to the events of September 11, 2001, U.S. President George. W. Bush declared war, not against any country, but against terrorism in general — which inevitably led to invasions of Afghanistan and Iraq. The war on terror has been going on for more than 2 years, and although the operation in Afghanistan is over (for now), the war is far from over.
By the time the U.S. withdrew its troops from Afghanistan, the country alone had invested nearly $2 trillion. The total cost of the war on terror to date is about $8 trillion, making it one of the most expensive wars in history.
12. Boer War
Cost: $35 billion* (adjusted for 2021)
Location: South Africa
Duration: 1899-1902
At the turn of the 20th century, Britain waged a bloody war with the Republic of South Africa and the Free State of Orange over its influence in the region. When the British repelled the boar troops, they quickly gained the upper hand.
In the 3-Year War that followed, the British hindered the wild boar forces' chances of victory by burning farms, destroying livestock, and exporting wild boar prisoners of war to distant British colonies. At the time, the cost of war was about $285 million, equivalent to $35 billion today.
13. The Spanish Civil War
Cost: $3.89 billion*
Location: Spain
Duration: 1936-1939
When the Government is unable to accept the decisions of the democratic process, the result is usually a civil war. This was exactly what happened in the late 1930s, when Spanish nationalists backed by Italy, Portugal, and Nazi Germany launched an uprising that defeated the Spanish government (backed by the Soviet Union, Mexico, and France).
By the end of the war, the Nationalists had spent about $2.04 billion, surpassing republicans ($1.85 billion) and eventually winning the war. The result was a Spanish dictatorship led by Francisco Franco that lasted for the next 36 years.
14. Kosovo War
Cost: $40.65 billion*
Location: Kosovo
Duration: 1998-1999
A few years after the end of the Bosnian war, the southern region, formerly known as Yugoslavia, found itself caught up in a war. The war between the Kosovo Liberation Army (KLA) and the Federal Republic of Yugoslavia lasted about a year and a half and ended when NATO airstrikes forced the Yugoslav army to abandon Kosovo.
Costing more than $40 billion, the Kosovo War, while short and localized, was one of the most expensive wars in history. Many cities in the central Balkans still feel the economic impact of the fighting.
15. World War I
Cost: $3.3 trillion (2021)
Location: Worldwide
Duration: 1914-1918
On July 28, 1914, a month after the assassination of Archduke Franz Ferdinand, a war unprecedented in the world broke out. Artillery was more powerful, and air and submarine attacks were added to the global war repertoire, with more than 20 million casualties.
More than $3 trillion* (in today's currencies) was used in World War I, most of it from Germany, Great Britain, France, the United States, and Russia (in that order). To give you an idea of how hard the German economy was hit by the war, a loaf of bread cost around $10 (about 428 billion Deutsche Marks at the time).
16. Napoleonic Wars
Cost: $1.4 trillion* (adjusted for 2021)
Location: Worldwide
Duration: 1803-1815
Napoleon Bonaparte is known as one of the greatest war generals of all time, and rightly so. After all, he did conquer much of the continent before, failing to invade Russia in 1812 and being defeated by the Seventh Coalition at the Battle of Waterloo in 1815, which ended Bonaparte's rule.
The 12-year-long war cost Britain an estimated $1.1 billion ($1.4 trillion in 2021) – more than twice the GDP at the time – which was funded by countless investors. Or, the French Empire gets what it needs from places that Napoleon conquered as he crossed the continent.
17. The Soviet-Afghan War
Cost: $50 billion*
Location: Afghanistan
Duration: 1979-1989
Some people refer to the Soviet-Afghan War as the Vietnam War between the Soviet Union and the United States, because, like the United States, the Soviets spent a long time in a foreign country and had nothing but waste of time and resources. Not to mention, the failed operations in Afghanistan are also considered one of the events that led to the collapse of the Soviet Union.
In a 10-year war on foreign lands, $50 billion is a relatively low cost compared to other wars of the past 50 years — and the biggest cost of this war is not even included in the total cost — to form the Taliban.
18. The Chinese Civil War
Cost: $706 billion* (adjusted for 2021)
Location: China
Duration: 1927-1935/1945-1949
19. Vietnam War
Cost: $1 trillion* (2021)
Location: Vietnam
Duration: 1955-1975
After the defeat of French troops in Vietnam in 1954, the United States supported democratic-minded South Vietnam in order to prevent communism from spreading throughout the Eastern world. Unfortunately, northern Vietnam was not keen on democracy, and 20 years of bloody conflict followed.
The U.S. was involved for 10 years, culminating in one of the biggest defeats in U.S. military history, losing about $843 billion in the total cost of a $1 trillion war. The cost of the U.S. war does not include the $22 billion it paid to veterans and their families as compensation for injuries sustained in the conflict.
20. Gulf War
Cost: $102 billion (2019)
Location: Iraq
Duration: 1990-1991
In 1990, in response to the ill-fated decision of former Iraqi dictator Saddam Hussein to invade and annex Kuwait, a coalition of nations larger than any country since World War II was formed. Operations Desert Shield and Desert Storm were an overwhelming success, and Hussein was forced to withdraw his forces to Iraq.
The seven-month Gulf War cost the 35-nation coalition about $60 billion ($102 billion, in 2019), and while more than 70 percent of the troops were provided by the United States, most of the costs (about $32 billion) were ultimately backed by the governments of Saudi Arabia and Kuwait.
21. The Second Sino-Japanese War
Cost: $4-100 billion (adjusted for 2021)
Location: China
Duration: 1937-1945
When much of Europe was drawn into World War II, China and Japan were at the height of the Second Sino-Japanese War, which began in 1937 as Japan attempted a full-scale invasion of China. The decision to bomb Pearl Harbor inevitably brought the United States into World War II, and the Allies came to Japan's doorstep, turning out to be more expensive than the war itself.
The Second Sino-Japanese War cost Japan an estimated $4-100 billion (adjusted to 2021). That's the equivalent of $500,000 a month — $1 billion — to fund the war they ultimately lost because of this big decision.
22. Civil war in Sierra Leone
Cost: $15 billion
Location: Sierra Leone
Duration: 1991-2002
In the early 1990s, the Government of Sierra Leone found itself mired in a civil war with the Revolutionary United Front (RUF). The first half of the war concerned Mainly Sierra Leone and its southern neighbour, Liberia, which supported the cause of the RUF. By the half of the Civil War, however, more than 20 countries had been involved.
During the 11-year civil war in Sierra Leone and its diamond-rich region, a large part of the $15 billion financial burden came from international aid – notably years of UN peacekeeping operations and British ground and air aid.
23. Second Congolese War
Cost: $8 billion*
Location: Congo
Duration: 1998-2003
After the end of the First Congo War, the Second Congo War began in only about a year. Much of central and southern Africa was involved as Congolese pro-government forces fought against rebels backed by Uganda, Rwanda and Burundi, making it one of the deadliest and most expensive wars in the world since World War II.
An estimated $8 billion was spent on the African World War, most of which came from trade minerals such as diamonds and other gemstones, but there were no winners because despite an agreement between the two sides to form a government of national unity, the country was in ruins and millions of people were displaced.
24. Spanish-American War
Cost: $10.33 billion* (adjusted for 2019)
Location: Cuba, Puerto Rico, Guam, Philippines
Duration: April 21 to August 13, 1898
What you're about to hear may shock you, but the Spanish-American War was fought indirectly because the United States was defending Cuba's right to independence from Spain. It took the U.S. military less than four months to defeat Spain's global army and claimed the Philippines, Guam and Puerto Rico as U.S. property.
For a war that lasts less than a third of a year, it will certainly cost a fortune (mainly because of the wide range of locations of the battle). The final bill for the Spanish-American War of 1898 is estimated at about $270 million (10.33 billion in 2019).
25. Mexican War
Cost: $2.72 billion (2019 adjustment)
Location: Mexico
Duration: 1846-1848
A year after Texas was annexed, Mexico and the United States disputed the location of the southern border of the newest state. The dispute turned into a war in 1846, when Mexican troops engaged troops sent by U.S. President Polk to the area. I'm sure you understand by now that Mexico didn't win the fight.
By not doing well enough to leave alone, Mexico ended up losing more than just the monetary costs of the war and what is now South Texas. By the end of the war, the borders of Utah, Nevada, Arizona, California and New Mexico had expanded to include more of what had once been Mexico.