There is a scene that tells the story of this war better than any summit: the pilot of a modern Western fighter jet flying a mission with nearly empty missile racks, falling back on the gun built into the aircraft.

According to a report by a specialist American military outlet, Ukraine's F-16s are facing a serious shortage of air-to-air missiles. The problem is with the American AIM-9 Sidewinder and AIM-120 AMRAAM - the first are short-range infrared-guided missiles, the second work at medium range. Both are now being strictly rationed.

The outlet cites a journalist who spoke with a senior commander in the Ukrainian air force. The commander, with the call sign "Phantom", confirmed that because of the missile shortage pilots have to use cannons against airborne targets. His request was blunt: more AIM-9s or AIM-120s for the fleet, plus new interceptors for the Patriot systems.

When the cannon becomes the main weapon

When there are no missiles, what is left is the 20mm M61 Vulcan. But a cannon means closing in - far closer to the target than any missile requires. Against small drones and cruise missiles that is a doubly bad deal: the target is small and fast, and the pilot has to fly into the range of the other side's fire to hit it.

The problem is broader than it looks at first glance. The AIM-120 is also used in the ground-based NASAMS systems, which means the same munition has several customers within the same defence. Every missile spent in the air is one missile fewer for protecting cities - and the other way round.

This is not the first time. Back in March it was reported that Ukraine's F-16 fleet had gone more than three weeks without enough American missiles, precisely when Russia was preparing an intensive air campaign. At that point Kyiv was said to have only a "handful" of Sidewinder missiles. The same problem is back six months later, which says this is not a supply incident but a structural hole.

An aircraft is not a package delivered once

Here is the lesson routinely missed in political announcements. Delivering fighter jets looks like the final act of support - the picture is good, the figure is concrete, the headline is strong. But an aircraft is a platform, not a solution. Without a constant supply of the right munitions it is expensive metal that flies.

At the same time, Ukraine's air defence is burning through enormous quantities of interceptors to protect cities and critical infrastructure, while Russia keeps increasing its use of drones. So Kyiv has a double problem: preserve Patriot missiles for the most dangerous targets, and simultaneously secure enough air-to-air missiles to keep the F-16s usable.

The question for Kyiv is therefore not how many aircraft are in the air, but how long it can keep them there with weapons inside them. That is a question every small army relying on someone else's deliveries should ask before showing off new equipment - is the thing that makes it usable coming too?