"U.S. Iran War Costs Estimated at $20–25 Billion in March… $650 Billion Annually for Full-Scale War, Says Quincy Institute"

According to recent analysis, the cost of the U.S. war with Iran was estimated to be between $20 billion and $25 billion during the first month of March. As military operations were heavily concentrated at the onset of the conflict and then decreased in intensity, it is expected that from April onward, costs will drop to approximately $250 million to $500 million per day, or $7.5 billion to $15 billion per month. While the probability is extremely low, if the United States were to invade and occupy Iran as it did during the Iraq War, the costs could reach $650 billion annually.

The Quincy Institute, a U.S. think tank, presented these findings in an article titled “Iran War Costs: What We Know and Where We Might Be Headed,” published on its website on April 7 (local time). The Quincy Institute is a new American think tank established in 2019.

The following is a summary of the main points.

March Cost Estimate: $20 Billion to $25 Billion

The Department of Defense has not yet released an official estimate of war expenditures. However, it is reasonable to assess that the costs borne by the Department of Defense during the first month of the war were in the range of $20 billion to $25 billion. The upper bound of this estimate ($25 billion) is based on the analysis and methodology developed by the Center for Strategic and International Studies (CSIS). The lower bound ($20 billion) is based on the analysis of U.S. air campaign costs during the 2003 Iraq invasion.

Future Monthly Cost Estimate: $7.5 Billion to $15 Billion

Because of the significant uncertainty surrounding U.S. war plans, ammunition consumption, and other variables, even rough projections of future costs for military operations against Iran are challenging. Nevertheless, it is possible to present a general range of potential future expenditures based on the course of the conflict.

In the first month of the war, U.S. military operations were primarily focused on airstrikes and missile attacks conducted by the Air Force and Navy, as well as air defense activities. These operations were especially intense during the first week, with the extensive use of expensive, long-range precision-guided munitions such as Tomahawk cruise missiles launched from naval vessels, resulting in particularly high costs during the initial days. Thereafter, at least until the weekend before President Trump set a deadline of April 6, the intensity of operations and the costs of deployed weaponry, while still significant, appeared to have generally declined.

Assuming the intensity of operations remains roughly at current levels going forward, a daily cost of $250 million to $500 million, or $7.5 billion to $15 billion per month, is a reasonable estimate. If U.S. operations further decrease in scale—for instance, if there are fewer valuable targets, if both sides step back, or for other reasons—the monthly cost could drop further, potentially falling to several billion dollars.

Conversely, if military operations are expanded, costs could easily rise. In fact, the administration has signaled it would escalate if the Iranian government ignores its recent ultimatum. In recent weeks, the U.S. military has begun deploying some Marine and Army units to the region, which could be used in ground operations inside Iran. This includes two Marine Expeditionary Units (MEUs) and one brigade from the 82nd Airborne Division. The specific use of these forces remains unclear. However, media reports and external analysts generally focus on scenarios in which these forces would seize Kharg Island, Iran’s main oil export hub, or Iranian-controlled islands near the Strait of Hormuz. Overall, it is believed that at least 7,000 combat troops and a substantial number of support personnel are included in these deployments.

Such operations would likely involve far more intensive air and missile campaigns, supported by U.S. Air Force and Navy assets, than seen in recent weeks. Furthermore, depending on the mission, objectives, and the evolving ground situation, significant additional forces could follow the initial deployments. For example, the remaining two brigades of the 82nd Airborne Division could be committed. Under these circumstances, instead of the April monthly cost dropping to $7.5 billion to $15 billion, as mentioned above, it could remain at or even exceed the $20 billion to $25 billion level estimated for March.

Could This Year’s War Costs Reach $200 Billion?

The White House is reportedly planning to request an additional budget of $200 billion to fund U.S. and Israeli operations against Iran. Can actual expenditures reach that level during the remainder of the fiscal year, which ends on September 30? In an extreme escalation scenario, it is certainly possible. However, for this to occur, the war must be greatly expanded beyond the illustrative scenarios previously presented, or the conflict must last much longer than the administration’s projected duration of four to six weeks.

According to this analysis, even a two-month conflict involving limited ground operations would likely cost around $50 billion, or perhaps somewhat less. To reach $200 billion, the scale and duration of the conflict would need to be dramatically expanded beyond these assumptions.

This article does not further speculate on the specific forms such an escalation might take. Such an expansion could involve a much larger build-up of air, naval, and ground forces in various proportions, and the duration could extend from several weeks to many months. For context, it is worth recalling that in 2008, at the peak of the Iraq War, the United States spent about $211 billion (in 2026 fiscal year dollars). This is only slightly more than what the Trump administration is now requesting for the war with Iran. At that time, an average of approximately 160,000 U.S. troops were actually deployed on the ground in Iraq.

Could the United States Conduct a Large-Scale Invasion and Occupation of Iran Like the 2003 Iraq War? Annual Costs Would Be $650 Billion

It is extremely difficult to imagine President Trump actually deciding to attempt such an invasion and occupation of Iran. However, if he were to do so, the financial costs would be immense. As noted above, at the height of the Iraq occupation in 2008, the United States maintained an average of about 160,000 ground troops in Iraq. Today, Iran’s population is more than three times larger than that of Iraq at the time, and its territory is roughly four times bigger. This suggests that the U.S. military might require at least 500,000 troops to carry out a similar mission. Such a scale would be exceptionally difficult to execute and sustain over the long term.

If we simply apply the per-soldier costs incurred in Iraq, maintaining such a force would amount to about $55 billion per month, or more than $650 billion annually. Even this likely significantly underestimates the true costs. Above all, in this case, there would be a lack of relatively safe bases in the Persian Gulf region to assemble and support U.S. ground forces, which could further drive up expenses.

This content was produced with the assistance of AI translation services.