Yep, that is Putin’s weakness, at least as viewed in Russia (based on reports, of course) - too damn soft! So, for all you Putin-haters, be careful what you wish for...
But there is actually a reason for Putin’s softness, but I’ll leave it as an exercise to the student to try to figure it out.
In my view, Putin just wanted the Russian speaking areas of Ukraine. His objectives were limited. Those keeping track of events in Ukraine noted that about 8,000, or so, Russian ethnics were slaughtered shortly before Putin declared war.
But there is actually a reason for Putin’s softness, but I’ll leave it as an exercise to the student to try to figure it out.
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Answer: Putin has to fix the Russian military first.