Question: which nation was america's primary enemy during the cold war
[{'answer': 'the Soviet Union', 'provenance': [{'wikipedia_id': '325329', 'title': 'Cold War', 'start_paragraph_id': 1, 'start_character': 58, 'end_paragraph_id': 1, 'end_character': 74, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]