A lasting Norse North America changes European expansion

What if Norse settlement spread across North America before Columbus?

Continued transatlantic contact could produce populous, fortified societies with European weapons, pushing Spain and Portugal toward other routes and conquests.

The scenario gives Norse settlers four centuries in North America before Columbus arrives, with many communities having lost contact with Europe. Some continuing trade is considered likely even if contact is uneven. That could leave the Spanish facing substantial armies, fortified settlements, and some firearms, making trade more attractive than an immediate attempt at conquest. Rivalry among Norse settlements provides a further reason for fortifications to develop. Spain and Portugal could still find places to establish colonies while turning toward India earlier.