Drone camera footage defines much of the public's view of the war in Ukraine: grenades quietly dropped on unwitting soldiers, eerie flights over silent, bombed-out cities, armour and outposts exploding into fireballs.
Never in the history of warfare have drones been used as intensively as in Ukraine, where they often play an outsized role in who lives and dies. Russians and Ukrainians alike depend heavily on unmanned aerial vehicles to pinpoint enemy positions and guide their hellish artillery strikes.
But after months of fighting, the drone fleets of both sides are depleted, and they are racing to build or buy the kind of jamming-resistant, advanced drones that could offer a decisive edge.
The urgency was reflected by the White House's disclosure on Monday that it has information that Iran will be rushing “up to several hundred” unmanned aerial vehicles to Moscow's aid.
Iranian-supplied drones have effectively penetrated US-supplied Saudi and Emirati air-defence systems in the Middle East.
“The Russian drone force may still be capable, but exhausted. And Russians are looking to capitalise on a proven Iranian track record," said Samuel Bendett, an analyst at the CNA military think tank.
Meanwhile, Ukraine wants the means "to strike at Russian command and control facilities at a significant distance”, Bendett said.
The demand for off-the-shelf consumer models remains intense in Ukraine, as do efforts to modify amateur drones to make them more resistant to jamming. Both sides are crowdfunding to replace battlefield losses.
“The number we need is immense,” a senior Ukrainian official, Yuri Shchygol, told reporters on Wednesday, detailing the first results of a new fundraising campaign called “Army of Drones”.
He said Ukraine is initially seeking to purchase 200 NATO-grade military drones but requires 10 times more.
Outgunned Ukrainian fighters complain that they simply don't have the military-grade drones needed to defeat Russian jamming and radio-controlled hijacking.
The civilian models most Ukrainians rely on are detected and defeated with relative ease. And it's not uncommon for Russian artillery to rain down on their operators within minutes of a drone being detected.
Compared with the war's early months, Bendett now sees less evidence of Russian drones getting shot down. “The Ukrainians are on the ropes,” he said.
Adding to the defenders' woes: The Ukrainian hero of the war's early weeks, the Turkish-made Bayraktar TB-2 laser-guided, bomb-dropping drone, has become less effective in the face of denser Russian air and electronic defences in eastern Ukraine. It was the star of many a patriotic Ukrainian video.
“Russians are in a much better position because they fly long-range drones" designed to evade electronic countermeasures, a Ukrainian air reconnaissance unit leader recently told Associated Press journalists outside Bakhmut near the front lines.
On the ground, Russia's more plentiful electronic warfare units can cut off drone pilots' communications, interrupt live video and drop the vehicle from the sky or, if it has homing technology, force it to retreat.
Hence the need for advanced drones that can survive radio interference and GPS jamming and rely on satellite communications and other technologies for control and navigation.