As Iran counters American and Israeli strikes with waves of drones that have at times slipped through air defenses, the U.S. is accelerating a long-running push to develop new technology and tactics for what is quickly becoming its first major drone war.
For help catching up -- it's looking to Ukraine.
While the Pentagon has spent years slowly folding drone tactics into its military doctrine, Ukraine has spent the past four years fighting a desperate war against Russia in which Iranian-made Shahed drones and other unmanned aircraft have emerged as a defining weapon of modern combat, giving Kyiv some of the most hard-won expertise in the field.
At the Trump administration’s request, Ukraine has dispatched drone warfare specialists, armed with drone interceptors, to a U.S. military base in Jordan, a Ukrainian official told ABC News, in addition to three Gulf countries.
In Jordan, Ukrainian drone operators, armed with interceptor drones, have been deployed to an American military base, a Ukrainian official told ABC News, as Iranian retaliation across the region has heavily relied on unmanned aircraft.
Ukrainian President Volodymyr Zelensky on Wednesday said that his top defense aide would visit the United Arab Emirates and Saudi Arabia to discuss military cooperation on the issue.
The rapid spread of inexpensive drones has increasingly blurred traditional front lines, putting even rear-area bases at risk.
Seven American troops have been killed in the war with Iran, including six service members who died in a single Iranian drone attack in Kuwait, a country long viewed as one of the safer places for American forces to deploy in the region. At least 140 troops have been wounded as of Thursday.
Drone warfare is in its infancy, current and former U.S. officials explained, as the blueprints for how to fight with them are being developed in real time.
Some of those tactics include the use of so-called drone swarms, dozens or potentially thousands of small drones armed with explosives converging on a single target at once, the premise being to overwhelm air defenses through sheer volume, betting that it only takes a few drones slipping through to deliver a devastating hit.
The U.S. has even reverse-engineered the Iranian Shahed into its own one-way attack drone, deploying them to the Middle East in December, making their combat debut in the opening hours of the war in Iran.
Pentagon planners are also figuring out how different drones perform in different climates, how they can be transported to forward positions, and how they can be launched from warships, vehicle-mounted systems, and improvised field setups, a U.S. official told ABC News.
The services are also experimenting with using drones as aerial pack mules, hauling ammunition and other gear across the battlefield.
Defending against drone attacks is a seismic shift for American military tactics as U.S. forces haven't had to take aerial attacks into account for more than a generation, one U.S. official noted.
"It's like how we introduced the tank in World War I, this is all new ... but we're completely rethinking how we fight," the official said on condition of anonymity because the person wasn't authorized to talk to the media.
Just as important are the economics. Drones cost a fraction of the weapons needed to shoot them down, a math problem that has vexed military planners for years.
"A couple of years ago, you'd always hear the same example: we're shooting down a $50,000 drone with a $2 million missile," Adm. Brad Cooper, the top U.S. commander in the Middle East, told reporters last week. "That equation is beginning to change," he said. "These days we're spending a lot more time shooting down $100,000 drones with $10,000 weapons [of] ours."
Denver Riggleman, a former National Security Agency analyst and Air Force intelligence officer who worked with drone manufacturers in Ukraine and even embedded with military units that "hunt" drones overhead with rifles, said he observed an "evolution in warfare" there.
"The war in Ukraine is the most comprehensive laboratory for advances in warfare we have seen in quite some time … generations," Riggleman said.
The Ukrainian defense industry, which is estimated to produce between four and seven million drones annually, has struck a key balance "between quantity and quality," said Riggleman, who also is a former GOP member of Congress from Virginia.
"[U.S.] technologies are really almost too exquisite for efficient production of drones," he said. "And Ukrainians have been able to balance building drones at a massive level with just enough quality to take out higher-end drones."
Ukraine's move to export its battlefield expertise to allies in the Middle East comes after President Donald Trump zeroed out military aid to Ukraine, who he said should rely on European partners instead.
Ukrainian and U.S. negotiators began talks on a drone deal over a year ago that would involve co-production of the weapons between the countries, including interceptors that would counter the offensive drone capabilities of countries like Iran.
Iran has unleashed its Shahed drones on Gulf neighbors since hostilities began. Its Shahed system has long been exported to Russia, where the Russian military has deployed the weapon against Ukraine.
The U.S. has even reverse-engineered the Shahed into its own one-way attack drone, according to Central command, deploying them to the Middle East in December, making their combat debut in the opening hours of the war in Iran.
In August, Zelenskyy told reporters that the Ukrainians proposed a co-production agreement with the U.S. to make 50 million drones over 5 years -- at a cost of $50 billion.
On Tuesday, he said that the drone deal under consideration last spring remains "very relevant" and that he hoped he could sign the deal with Trump.
He said there was a "postponement" of the agreement, but did not offer why it was never signed.
ABC News has reached out to the White House for comment about the proposed drone deal and whether it remains under consideration by the administration.