Why Baltic-state submarines need a regional comparison

What about the submarines of Latvia, Lithuania, and Estonia?

They warrant a separate Baltic study, especially linking Estonia with Finland and their common Soviet threat.

The Baltic states are not folded into the four-navy lecture because their procurement story forms a distinct regional system. Estonian boats in particular make more sense beside Finnish designs and the shared strategic problem posed by the Soviet Union. Their programs influenced one another and included boats closely connected to German design development. A separate comparison would therefore explain regional force planning better than appending isolated hulls to this four-navy survey.