A farm might depend on neighboring farms.

The church might depend on tithes.

Trade might depend on ships arriving from Iceland or Norway.

Imported iron could matter disproportionately because Greenland did not possess abundant local sources suitable for all of the metal needs of a medieval European society.

This meant the Greenland colony was never entirely self-contained.

It was an island society connected to a much larger network.

And networks can fail quietly.