Incomprehensible barriers, that is, the effectiveness of strengthening border protection

We would like to ask why the construction of a barrier on the border with Russia - although it could be expected that it would be inevitable - raises specified opposition, despite the fresh conditions at the Polish borders. Since 2021, 2 countries, namely Belarus and Russia, have been seeking to make force on a number of NATO and EU members, utilizing intellectual but besides physical tools in the form of migration pressure. Therefore, a fewer words of reflection on how to talk about strengthening safety - not only at the border with Belarus, but besides at the border section with Kaliningrad, belonging to Russia.