I don't have high hopes in NATO, but I really doubt that would happen
NATO and the EU are useless - NATO depends on the US, EU is toothless and their biggest military power - France is Russian slut.
The only solution would be to show strength NOW - deploy nuclear weapons to the Baltics and deal with every single fifth columnist there in a brutal, public fashion. Of course this will never ever happen. Annexation is matter of time.
I'm moving away from Tallinn next year, so hopefully this year nothing will happen...just in case I have all my money moved out of the country.