Estonian Foreign Minister Margus Tsahkna said in an interview that Russian troops attempting to breach the Estonian border without insignia would be met by force.
Archived version: https://archive.is/20251225205454/https://www.kyivpost.com/post/66868
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That goes without saying. My intention was to say that threats are not enough. Russians will test them and if they are not acted upon they will take that as a sign of weakness and they will do it again and again and again.
I don’t think Estonia will have empty “red lines” like Russia does.