Among the many bizarre White House conversations between President Richard Nixon and his national security adviser Henry Kissinger that Gary Bass cites in his devastating account of America’s role in the creation of Bangladesh, a particularly wrenching one took place in April 1971, a little over two weeks into an onslaught by the Pakistani military upon its own citizens.

Sparking the Nixon-Kissinger exchange was an indignant diplomat named Archer Blood, the U. S. consul general in Dacca, the capital of Pakistan’s eastern half. For a fortnight, Blood had been cabling Washington details, meticulously gathered by his staff, of massacres and expulsions that had left the Bengali city “a ghost town.” Kissinger had downplayed the details of these reports to the president, and made clear to his aides that they should ignore the dispatches, even as three fourths of Dacca’s population fled for their lives.

On April 6, disgusted by Washington’s silence, Blood and his staff transmitted to their superiors in Washington a collectively authored telegram registering official disagreement with American policy: the “Blood telegram” of Bass’s title. It used the word “genocide” to describe the killings in Bengal, which were targeting the Bengalis—and specifically the Hindus among them—of East Pakistan. It was, Bass writes, “as scorching a cable as could be imagined” and “probably the most blistering denunciation of U. S. foreign policy ever sent by its own diplomats.” The five-page cable catalogued the “moral bankruptcy” of America’s Pakistan policy in failing to denounce the atrocities, in condoning the suppression of democracy, and in continuing to support and to arm the fast-dissolving country’s military leader.

Less than a week later, Nixon and Kissinger met in the Oval Office to try to convince themselves of the rightness of their dedication to that military leader, General Yahya Khan. He was a Sandhurst-trained officer straight out of central casting, complete with swagger stick, strut, and slick-backed hair. Nixon admired him and considered him a friend. Kissinger privately judged him a moron, but saw in him a supremely useful instrument to pursue America’s geopolitical interests. Now, as Yahya pressed his American-equipped army into service against Pakistan’s Bengali population, he was becoming an awkward problem for his Washington backers. The contents of Blood’s denunciatory cable had spread fast, winning supporters within the State Department and reaching the press and Democratic leaders. (Blood had taken care to give the telegram a low classification—merely “Confidential.”)

Infuriated by Blood’s insubordination and anxious that his message could derail their Pakistan policy, Nixon and Kissinger stiffened their commitment to Yahya. Biafra, Nixon suggested to Kissinger, had been worse than what was happening in East Pakistan—but the United States had not intervened there. Would it not be moral hypocrisy to intervene in Bengal? Or was Biafra’s neglect justified because it had fewer people? And for that matter, Nixon mused (maybe forgetting that his adviser’s own family had fled Nazi Germany), could it be said that because “there weren’t very many Jews in Germany” perhaps it was “therefore not immoral for Hitler to kill them?”