How do you think other european nations will threaten spanish and portuguese power in the americas?

The correct answer is by force

They can't threaten them with religious spread or with economic developments because they were weaker than Spain in that area, however, they had massive armies that could take areas of land by force. For example, the British fleet managed to beat the Spanish armada and take control of the seas and the oceans.

In the midwest because it has more moderate climate than the north or south west which makes farming far easier.