Russia losing the strategic initiative in Ukraine

 ISW:

Ukraine is likely seizing the strategic initiative and forcing Russia to reallocate forces and reprioritize efforts in response to Ukrainian counteroffensive operations. Russian forces are increasingly transferring personnel and equipment to Kherson and western Zaporizhia Oblasts at the expense of their efforts to seize Slovyansk and Siversk, which they appear to have abandoned. Russian forces are also redeploying military equipment – artillery and aviation in particular – to Crimea from elsewhere in Ukraine. Russian forces have previously withdrawn from or suspended offensive operations on Kharkiv City and the southern axis to prioritize capturing Luhansk Oblast, but they did so on their own initiative based on the changing priorities of their commanders. Russian forces in this case appear to be responding to the Ukrainian counteroffensive threat in Kherson Oblast rather than deliberately choosing objectives on which to concentrate their efforts. Even after Ukrainian forces defeated the Russian attempt to seize Kyiv early in the war, the Russians were able to choose freely to concentrate their operations in the east. Ukraine’s preparations for the counteroffensive in Kherson and the initial operations in that counteroffensive combined with the dramatic weakening of Russian forces generally appear to be allowing Ukraine to begin actively shaping the course of the war for the first time.

The seriousness of the dilemma facing the Russian high command likely depends on Ukraine’s ability to sustain significant counteroffensive operations on multiple axes simultaneously. If Ukraine is able to press hard around Izyum as it continues rolling into the counteroffensive in Kherson, then Russian forces will begin confronting very difficult choices. They will likely need to decide either to abandon their westward positions around Izyum in favor of defending their ground lines of communications (GLOCs) further north and east or to commit more personnel and equipment to try to hold the current front line. Such forces would have to come from another axis, however, putting other Russian gains at risk.
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This has the potential to be a turning point in the Russian war effort.  It exposes the Russian shortage of combat power and forces undesired troop movement requirements on the Russian command.  I suspect that the HIMARS attacks have also weakened the Russian ability to respond because of the shortages of supplies. 

See, also:

Russia’s Shortfalls Create an Opportunity for Ukraine, Western Officials Say

• Severe equipment and manpower problems could slow President Vladimir Putin’s mission as the war enters its sixth month.
• Ukraine is taking advantage by launching a counteroffensive, with more likely in the coming weeks, according to U.S. officials.