Europe has the worst and the most vulnerable geography

Which country in Europe has the worst and the most vulnerable geography?

Poland, Ukraïna, Belarus, Moldova, Western Russia are at the top of the list within Europe. This extends to Western-most Kazakhstan as well.

The countries are within the Eastern European Plain:

Part of the Greater European Plain:

Here is another relief (extending deep into Asia):

These flat lowlands a part of/connected to what is known as the Eurasian Steppe.

This open flatland is another very defensiveless position for terrestrial attack. (Note: Mongolia's flatlands are raised, offering some shield N-S, but otherwise still directly connected.) The steppe have for millenia been an open E-W avenue of invasion, migration, transit, diffusion and trade.

Picture Source Wikipedia

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