As Russians dig in, their effort to get more troops into Ukraine stalls too

 ISW:

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Russian efforts to bring Syrian forces into Ukraine may be encountering challenges. Ukrainian military intelligence (GUR) reports that a Russian commander in Syria met with the commander of the Syrian Arab Army’s 8th Brigade to request a list of Syrian personnel ready to fight in Ukraine, but that the Syrian commander promised only to respond after consulting with his colleagues.[1] We have no independent verification of this report. ISW’s Middle East Team is preparing a brief report on Russian efforts to mobilize Syrian forces to support the war in Ukraine and will publish it in the coming days.

Russian mobilization efforts are likely becoming urgent given Russian losses in the war. The Wall Street Journal cites an unnamed NATO official claiming that Russia has lost as many as 40,000 troops killed, wounded, or missing of the roughly 190,000 deployed to invade Ukraine.[2] That assessment, which is plausible given previous estimates of Russian combat deaths, must be considered in the context of the assessment offered by an unnamed Department of Defense official on March 21 that Russia had committed a high proportion of its available battalion tactical groups to the war already.[3] The protracting pause of Russian offensive operations in Ukraine and increasing anecdotal reporting of breakdowns in the morale and capability of Russian combat units all accord with these assessments. These reports and assessments collectively suggest that Russia may not be able to find new combat power with which to regain offensive momentum for weeks or even months.

Russian forces are increasingly preparing for protracted defensive operations in various parts of the theater. Numerous reports and satellite images of Russian troops digging defensive positions and laying mines suggest that they have gone over to the defensive and do not anticipate conducting renewed large-scale offensive operations in the near future in a number of locations across Ukraine.
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Ukrainian forces have launched counterattacks to regain territory occupied by Russian troops, liberating the town of Makariv as noted in the update of March 22. The counterattack, probably conducted primarily by Ukrainian forces from the west of the forwardmost Russian positions, has likely made more significant progress than our map of March 22 showed....

Local Ukrainian officials claimed on March 23 that Ukrainian forces have encircled Russian troops in Irpin, Bucha, and Hostomel.[4] The mayor of Kyiv claimed that Ukrainian troops have almost pushed Russian forces out of Irpin.[5] The mayor of Irpin claimed that Ukrainian forces controlled 80% of the city as of March 23 but noted that the Russians continue to fire mortars and Grad rockets at the town and that Russian saboteurs and looters are pervasive.[6]

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The post right before this one is from Twitter and it shows what looks like a naval disaster for the Russians.  Up until now, that had been one area where the Russians had had some success. 

The Russian troops going on the defensive appear to be at the end of the Russian supply lines and may have trouble getting food and ammo as the Ukraine forces begin to move against them.  Those at the extreme of the supply lines have often been stalled by the lack of fuel and food.

I suspect one of the reasons the Russians are having trouble recruiting new fighters is their lack of success on the battlefield so far.  Persuading mercenaries to die for a lost cost is a tough sell.  As the Russian disasters multiply. the will of the Russian leadership will be challenged even more.