They simply chose not to do anything about it.

When CIA-backed Afghan warlord Abdul Rashid Dostum had up to ’several thousand’ Taliban prisoners sealed and suffocated to death in metal shipping containers just days after the United States invaded the country, it did not go unnoticed by the White House. They simply chose not to do anything about it and quietly worked to discourage efforts to uncover the truth, according to a late-Friday report by The New York Times...Link