The threat to the survival of which nation led the Allies to pursue a “Europe-first” strategy?

norsemen from northern countries had made earlier journeys

answer: b.

explanation:

roosevelt believed that in light of the country's recent military successes, it was unnecessary to use force to achieve foreign policy goals, so long as the military could threaten force. this belief, and his strategy of “speaking softly and carrying a big stick,” shaped much of roosevelt's foreign policy.