The U.S. is the biggest military power in the world, with an annual budget of $649B. The War in Afghanistan in total has cost the country over $910B. The conflict is now over 18 years old, making it by far the longest in American history. It’s so old, some soldiers preparing to fight in it were not even born when it started. Time Magazine calls it “America’s Forever War,” which got us thinking about how its price tag compares to other wars in American history.

• World War II is by far the most expensive in American history, totaling 4.69T, more than every other war combined.
• The War in Afghanistan is only the third most expensive, however it is by far the longest at 18 years and counting.
• The total cumulative cost of the Civil War for both the North and the South is surprisingly small.
• Warfare is getting more expensive over time thanks to pricier weapons and far-off conflict zones.

We plotted each war on a timeline from the American Revolution until today, illustrating how long each conflict lasted, where in the world it took place, and how much each one cost. You can read the details about how the Congressional Research Service calculated the costs of war in the full report. Our figures from USA Today are adjusted for inflation in 2019 to represent a true apples-to-apples comparison. The visualization reveals several key trends and takeaways about the true cost of warfare. Warfare has cost the American people over $8.6T, to say nothing of the lives lost. That’s the equivalent of over one-third of the entire U.S. national debt ($22.8T), or about twice the size of the GDP of Japan ($4.6T).

Top 10 Most Expensive Wars in U.S. History

1. World War II: $4.69T
2. Iraq War: $1.01T
3. War in Afghanistan: $910.47B
4. Vietnam War: $843.63B
5. Korean War: $398.81B
6. World War I: $381.8B
7. Persian Gulf War: $116.6B
8. Civil War: Union: $68.17B
9. Civil War: Confederacy: $22.99B
10. Spanish American War: $10.33B

War also tends to get more expensive over time, steadily rising from a few billion dollars to just shy of trillions by the twenty-first century. This is thanks in large part to the cost of complex weapons systems, like the F-35 Lightning fighter jet, which has a lifetime cost to the U.S. military of $1T. We should also mention how the location of combat determines how much it costs. In the first several decades of American history, wars typically occurred close to American borders, usually somewhere in North America. But then the U.S. became engaged in global conflicts and in theaters of combat literally around the world, like Iraq and Afghanistan. These wars create complicated supply lines, further driving up the cost.

All that being said, nothing compares to the truly staggering cost of World War II at $4.69T. No other war even comes close to costing as much, and in fact the cumulative total of every other war in American history is just $3.77T. Although the War in Afghanistan is the longest in history, it has a long way to go before it will be as expensive as World War II.

How expensive do you think the War in Afghanistan will ultimately be? Let us know what you think in the comments.