| CAP | combat air patrol |
| CAPPS | Computer Assisted Passenger Prescreening System |
| CENTCOM | Central Command |
| CIA | Central Intelligence Agency |
| CONR | Continental U.S. NORAD Region |
| CSG | Counterterrorism Security Group |
| CTC | Counterterrorist Center |
| DIA | Defense Intelligence Agency |
| DCI | Director of Central Intelligence |
| ESU | Emergency Service Unit (NYPD) |
| FAA | Federal Aviation Administration |
| FBI | Federal Bureau of Investigation |
| FDNY | Fire Department of New York |
| FFTC | Florida Flight Training Center |
| FISA | Foreign Intelligence Surveillance Act |
| FISC | Foreign Intelligence Surveillance Court |
| INS | Immigration and Naturalization Service |
| ISID | Inter-Services Intelligence Directorate (Pakistan) |
| JCS | Joint Chiefs of Staff |
| JI | Jemaah Islamiah |
| JTTF | Joint Terrorism Task Force |
| KSM | Khalid Sheikh Mohammed |
| Legat | legal attaché |
| MAK | Mektab al Khidmat |
| MON | memorandum of notification |
| NEADS | Northeast Air Defense Sector |
| NCTC | National Counterterrorism Center |
| NGO | nongovernmental organization |
| NMCC | National Military Command Center |
| NORAD | North American Aerospace Defense Command |
| NTSB | National Transportation Safety Board |
| NSA | National Security Agency |
| NSC | National Security Council |
| NSPD | national security policy directive |
| NYPD | New York Police Department |
| OEM | Office of Emergency Management (New York City) |
| OFAC | Office of Foreign Assets Control |
| OIPR | Office of Intelligence Policy and Review |
| OMB | Office of Management and Budget |
| PAPD | Port Authority Police Department |
| PDD | presidential decision directive |
| PEOC | Presidential Emergency Operations Center |
| SEC | Securities and Exchange Commission |
| TSA | Transportation Security Administration |
| TTIC | Terrorist Threat Integration Center |
| UBL | Usama Bin Ladin |
| WMD | weapons of mass destruction |
| WTC | World Trade Center |
| WTO | World Trade Organization |
Transcribed and formatted for HTML by Jerry Holden for the HyperWar Foundation