Ukraine at D+258: Russia retreats from Kherson.

Russian forces ordered to withdraw east of the Dnipro.

This morning Russian Defense Minister Shoigu ordered Russian forces holding the line in the vicinity of Kherson to abandon the city and withdraw east of the Dnipro River, the Guardian reports. "General Sergei Surovikin, in overall command of the war, recommended the withdrawal of Russian troops from the west bank of the Dnieper River, citing logistical difficulties. 'Kherson cannot be fully supplied and function. Russia did everything possible to ensure the evacuation of the inhabitants of Kherson.' Surovikin told Shoigu. 'The decision to defend on the left bank of the Dnieper is not easy, at the same time we will save the lives of our military.'” The New York Times calls the retreat "a potentially serious blow to President Vladimir V. Putin’s war effort," which surely it is.

Mr. Shoigu's announced his decision to order the retreat on Russian television. His gloss on his reasons (in a translation from Smotri Media provided by the Guardian's Luke Harding) is implausible, but the effect of the order is unmistakable. "The lives and health of our troops always takes priority. Take into account the threat to the civilian population and respect the wishes of those who wish to leave. And secure the transfer of military equipment across the Dnipro."

In principle, shorter lines and static, well-prepared positions are easier to defend, but infantry occupying such positions and unsupported by combined arms can also be reduced by intelligently applied fire. But general Russian logistical failure would render even well-led, well-prepared defenses untenable. (And the Russian defenses, betting on form, are unlikely to be either well-prepared or well-led.)

Fragile lines of communication into southern Ukraine.

The Russian retreat from Kherson brings renewed attention to the fragility of Russian logistics, shaky enough under the best of circumstances, but especially stressed in the southern front. Consider that the bridge over the Kerch Strait from Russia to occupied Crimea is unlikely to return to full operation until September of next year, and that assumes no further disruption. In this morning's situation report, the UK's Ministry of Defence (MoD) explained the process of repairing the bridge. "Russian efforts to repair the Crimean Bridge continue but it is unlikely to be fully operational until at least September 2023. On 8 November the road bridge was due to be closed to allow the movement and installation of a replacement 64-metre span. Three more spans will be required to replace the damaged road sections. Although Crimean officials have claimed these additional spans will be in place by 20 December, a briefing provided to President Putin added that works to the other carriageway would cause disruption to road traffic until March 2023. Replacement of the damaged rail bridge has been contracted for completion by September 2023, although Russia’s Deputy Prime Minister stated the repair timeline would be expedited. One track is open, but rail transport remains restricted. Repair activity will be heavily dependent on weather conditions through the winter months."

The bridge is both a source of Russian national pride and a vital logistics route into Crimea and thence southern Ukraine. The MoD describes the logistical implications of damage to the structure. "The Crimean bridge attack has disrupted Russian logistics supplies for Crimea and southern Ukraine, reducing Russia’s ability to move military equipment and troops into the area by rail or road. The damage to the bridge, the recent attack on the Black Sea Fleet in Sevastopol and the probable withdrawal from Kherson all complicate the Russian government’s ability to paint a picture of military success."

Communications security lessons learned.

BlackBerry looks at the war against Ukraine and draws some lessons for communications security. They're old lessons, the kind that every war re-teaches (BlackBerry opens with a quotation from the Roman historian Suetonius describing Caesar's use of substitution ciphers), but they're worth reviewing nonetheless. The central lesson is that one should expect one's communications to be intercepted. Whether the opposition can read them in time to use them depends upon the effectiveness (and the general use) of your encryption. BlackBerry points out that businesses as well as armies should keep this in mind.