in bid to halt migrants
Ten Years too late. The rest is "signaling" for both Russian consumption and allied consumption, at the political level.
As a senior Army officer once described it to us (not a direct quote, paraphrasing)
"... when the 82d airborne was quickly deployed into the Mideast after Saddam invaded Kuwait, the first 72 hours was a calculated strategic risk intended to send a signal ... but the iron majors in the plans and ops shops referred to them as the "82d speed bump division" until more and heavier forces had deployed into theater."
Speed bump battalions, at the moment, but mostly sending a political signal.