Think about a hypothetical strategy to use ground forces - fully avoiding to escalate to a nuclear war - to actually assault baltic NATO countries. You just can't deploy massive russian forces to the NATO's frontier without triggering countermeasures.

But, if you massively deploy troops into Ukraine, simulating it is the target, then you start to pump troops, hardware, infrastructure for the actual invasion, NATO has to operate necessarily under the premise Russia isn't there to attack NATO, then it cannot massively deploy reinforcements to baltic members. They are by any military measure - except nuclear deterrence - undefendant.

Russian generals just have to sustain the maskirovka enough time to build up a sufficiently capable strike force to attack, basically a replay of the first movement against Ukraine. Then they could be in position to attack Poland, unbalancing NATO, triggering a defensive position in this country, then russians could invade the baltic states ("recovering" the whole old Eastern Europe of URSS age),

Then they could just abandon Poland, fastly signing an armistice but retaining the baltic states.

Europe as a whole probably will just sign the accords, in order to prevent a full nuclear escalation.

Game over. NATO has lost.

I also share this, but I find it increasingly concerning. If Putin has reached the point where a very risky war has to be waged against Ukraine, it means that he had worse options than the war. What options would be that?

A coup in process in Russia? Some military / oligarchic faction which already has reached the upper echelons of powers in Russia and they are forcing Putin's hand?

What internal restrains could Putin still retain, for how much time?

Is an escalation of hostilities in the cards? Has this already started and the whole Ukraine operations are just a maskirovka? (this last one is commonly mentioned everywhere these days, it seems everyone suspect the russians are not actually that weak and powerless to win a war, and they are just waiting for to deploy the full war machine against the actual targets).

https://en.wikipedia.org/wiki/Russian_military_deception

Kind of tense wait till this ends ..or it actually start to unfold.

Actually, most if not all the support for Ukraine looks awful a lot like they are trying to gain time to build up back some military strenght into EU.

I suspect if you start to peek behind the curtain, you'll find Reforger alike - or even the step-by-step actual Reforger - actions ongoing right now. At full speed.

Some other red flags would be the quick replacement of key - rather old, unfit for combat duty - officers across NATO forces, fleets of planes constantly being flown out of usual airbases (to prevent massive loses in a surprise attack), big bases in NATO countries emptied of troops (deploying troops in a very wide geographically distributed fashion, to protect them from being mass destroyed - soldiers + hardware - in a surprise attack), many trains and planes traveling / flying with closed windows at very unsual times, to fastly move troops across Europe to be ready for the probably coming war.

https://en.wikipedia.org/wiki/Exercise_Reforger