WASHINGTON, July 19 — Operation Inherent Resolve, the U.S.-led coalition campaign against the Islamic State in Iraq and Syria, has been running for more than a decade, yet it remains one of the most sprawling and costly overseas missions Americans rarely hear about. Think of it like a security patch you install on your phone — essential background work that keeps a persistent threat from breaking through, but easy to forget once it’s running.
Here’s what that actually means in boots on the ground, airstrikes in the air, and dollars out of the Pentagon budget. The operation, launched in June 2014, now involves 31 countries, though the United States provides the majority of forces and the bulk of air power.
As of 2023, the U.S. kept roughly 900 troops in Syria and about 2,500 in Iraq under the OIR banner. In Syria, those forces are primarily stationed in the northeast, including bases near the city of Hasakah — the same area where a deadly drone attack struck in March 2023. Since 2014, the coalition has carried out over 35,000 airstrikes across Iraq and Syria.
To put that in practical terms: those strikes cost an average of $8 million per day. The total price tag for U.S. military operations in Syria alone, from 2014 through 2021, came to $15.4 billion, according to the Pentagon.
The Human and Financial Cost
The practical upshot: the mission is expensive and carries real risk, even in what the Pentagon calls a “defeat-ISIS” campaign rather than a full-scale war. As of 2022, 13 U.S. service members had been killed in hostile action in Syria since the start of Operation Inherent Resolve. That number doesn’t reflect non-hostile deaths or injuries — the Pentagon has not released a comprehensive casualty figure for that period, so it’s hard to know the full human toll.
And the financial burden isn’t static. The $8 million per day figure covers airstrikes only — logistics, intelligence, and personnel costs push the overall expense higher.
For perspective, the $15.4 billion spent in Syria over seven years is roughly equivalent to what the U.S. spends on some major NASA programs over a similar span, though without the same clear exit strategy.
A Dangerous Escalation in 2023
Attacks on U.S. bases have surged in recent years. From January through October 2023, at least 180 attacks were recorded on American forces in Iraq and Syria, using rockets, drones, and mortars. That marks a sharp increase from previous years, though the source material doesn’t give exact earlier figures.
One of the deadliest incidents for U.S. personnel in Syria that year came on March 23, 2023, when a drone strike hit a base near Hasakah. The following day — March 24 — the coalition conducted airstrikes under OIR’s mandate to defend coalition forces.
Those strikes were the fourth such round of retaliatory action under the operation’s rules of engagement. The Pentagon has not disclosed how many militants were killed or what specific targets were hit, keeping the details under wraps for operational security. The practical upshot: the U.S. presence in Syria remains a lightning rod for attacks, and the coalition’s mandate means it can strike back swiftly.
That cycle of attacks and responses is likely to continue as long as troops remain deployed. With no official end date for Operation Inherent Resolve, the mission — and its cost in both lives and treasure — grinds on through a shifting landscape of regional rivalries and residual ISIS cells.
What to watch next: whether the 2023 escalation pattern holds into 2024 and beyond, and whether the Pentagon adjusts its posture to reduce vulnerability to drone strikes.
