Putin and his lackeys are already saying that Russia is at war with NATO, so turning empty bluster into reality would not provide any meaningful PR within Russia itself and would risk the total destruction of his Potemkin military. The only way in which a direct assault on NATO countries would make sense is if Putin believes he could get away with using tactical nuclear weapons, but here the risk is uncontrolled escalation that rapidly leads to all major Russian cities being reduced to radioactive rubble. So far, Putin has actually been quite cautious as he - probably correctly - believes Western resolve and Western capacity will run out long before he runs out of warm bodies to throw into the fray.