The war in Ukraine will be won by whichever side maintains its supply lines the longest.

Ukrainian forces have wrecked the Russian military by disrupting its ability to resupply its troops. Early on, that meant targeting Russian trucks with shoulder-fired missiles; lately it has meant precision long-range HIMARS strikes on railways and bridges. As a result, Russia’s ability to keep its men fed, fueled, and fighting has been so badly degraded that it was forced to take the unthinkable step of abandoning Kherson last month.

Kherson had been occupied since the first days of the war. Its proximity to Crimea made it easy in theory to keep the necessities of combat flowing to occupation forces there. Moscow even formally “annexed” Kherson oblast in late September, committing the Russian military to its eternal defense.

Six weeks later, fearing that all means of resupplying front-line troops would soon be extinguished, the Russian command pulled out. It was Ukraine’s greatest victory of the conflict, a gross humiliation for Putin given that he had declared the area part of Russia proper. And it placed Ukrainian artillery closer to Russian supply lines in parts of the country that have been occupied by Moscow for years, threatening to turn a war of conquest into a net loss of territory for the occupiers.