National Critical Capabilities Defense Act of 2020 This bill establishes the Committee on National Critical Capabilities to review specified forms of outbound investment, including any merger, acquisition, or takeover of a foreign person by or with a U.S. business that could result in a threat to national critical capabilities. Further, the bill establishes a congressional commission to review the activities of the committee, and it authorizes the President to suspend or prohibit transactions that pose a threat to national critical capabilities.