It's the foreign policy Theodore Roosevelt used, "Speak softly, and carry a big stick"
How was Durer's depiction different from most representations of this event? Most had the horsemen lined up in a row, while Durer created a compact overlapping ground of wild riders.
Spain (and Portugal) wanted to find a sea route to Asia because Portugal did not share trade routes with Asia and Europe (no Meditteranean Ports), Spain wanted to Spread Christianity, and both countries wanted to find more trade.