The communication and ongoing relationship between America and other world nations is known as <em>Foreign Policy.</em> <em>The president of the United States as head of the Executive Branch is responsible for the U.S. Foreign Policy. </em> In order to help him with these responsibilities the US President has the Secretary of State. This person acts as the equivalent of a Minister of Foreign affairs. Also the U.S. Ambassadors are responsible for the diplomatic relations with each country the U.S.has relations with. They are also part of the Foreign Policy area of the Executive Branch of Goverment ultimately led by the President of the United States.
The answer is no. If the spanish reconquest had failed, they would not be able to hold onto the iberian peninsula, which was ultimately where most of the voyagers to the new world began their journeys.
