The Netherlands made an unexpected leap forward in global politics. When it became clear that things needed to change, those pale-skinned people of the lowlands came up with a new plan: distributed feudalism.
While the Z-Virus was still raging around, a new entity declared itself to rise out of the ashes. The Pristine Dominion of the Netherlands, an organization of semi-autonomous city-states, banded together to maintain their dangerously-eroded dams. The new form of government, in which each city governed itself but owed service to the other cities of the Dominion, worked remarkably well in the post-apocalyptic chaos. The dams were repaired before another disaster fell, and the PDN became a world power by dint of being present in the world when most other governmental organizations had crumbled.
As time passed and neighbors saw the success, more of the cities of northern Europe were written into the constitution. Most of the remaining inhabited areas of non-Mediterranean Europe are now in some way tied to the PDN – many cities technically included, but acting as mere affiliates, and a few vice versa. Berlin, home of the Eisenjaeger Corporation, is a good example of the independent affiliate, with minimal ties to the other city-states other than mutual police cooperation.
The PDN proper – that is, the originating six surviving cities of the Netherlands – are only approachable from land by way of a series of gates; the dams extend to walls on the landlocked side.