Ukraine is running out of the missiles it needs to shoot down Russian attacks, and that is deadly news for its civilians as Russia ramps up strikes.

• A recent Russian barrage on Kyiv killed at least 17 people, and every one of the 28 missiles fired got through with none intercepted.
• Ukraine's air defense is layered, but the top layer that stops fast ballistic missiles relies on scarce, costly systems like the US Patriot and Europe's SAMP-T.
• Russia now builds up to 100 missiles a month and floods each attack with cheap drone decoys first, wearing down Ukraine's defenses before the real missiles arrive.
• The interceptors can't be replaced fast — a single Patriot missile costs up to $4 million and orders take about two years to arrive, worsened by the Iran war draining US stockpiles.
• North Korea is now sending Russia missiles and troops, having earned up to $13.6 billion, which buys Russia's arms makers time to catch up.

Outlook: Ukraine can't fix the shortage before winter, so expect deadlier strikes on cities and power grids on both sides in the coming months.