Question: what was the american policy toward the end of the vietnam war
[{'answer': 'Containment', 'provenance': [{'wikipedia_id': '425279', 'title': 'Containment', 'start_paragraph_id': 0, 'start_character': 0, 'end_paragraph_id': 0, 'end_character': 11, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}]