To monopolize the scientific data gained by Japanese physicians and researchers from vivisections and other barbarous experiments performed on living humans in biological warfare programs such as Unit 731, immediately after the war the United States (US) government secretly granted those involved immunity from war crimes prosecution, withdrew vital information from the International Military Tribunal for the Far East, and publicly denounced otherwise irrefutable evidence from other sources such as the Russian Khabarovsk trial. Acting in “the national interest” and for the security of the US, authorities in the US tramped justice and morality, and engaged in what the English common law tradition clearly defines as “complicity after the fact.” To repair this historical injustice, the US government should issue an official apology and offer appropriate compensation for having covered up Japanese medical war crimes for six decades. To help prevent similar acts of aiding principal offender(s) in the future, international declarations or codes of human rights and medical ethics should include a clause banning any kind of complicity in any unethical medicine—whether before or after the fact—by any state or group for whatever reasons.