# Post-9/11 Security Architecture September 11 exposed a system failure: relevant observations were distributed across institutions whose identities, databases, authorities, and analytic pictures did not align quickly enough. The response produced an enduring architecture of fusion, screening, task forces, interagency coordination, and interoperable information systems. The federal route runs through the [[wiki/Intelligence Community|Intelligence Community]], [[wiki/Federal Bureau of Investigation|FBI]], [[wiki/Department of Homeland Security|DHS]], [[wiki/National Counterterrorism Center|NCTC]], [[wiki/Joint Terrorism Task Force|JTTFs]], [[wiki/National Network of Fusion Centers|fusion centers]], [[wiki/Defense Threat Reduction Agency|DTRA]], [[wiki/Department of Defense|DoD]], [[wiki/United States Department of the Treasury|Treasury]], and [[wiki/Homeland Security Investigations|HSI]]. [[wiki/United States Army Intelligence|Army Intelligence]] supplies a scale of infrastructure and reachback that popular accounts often miss. The participant ecology is broader than permanent federal employees. State and local officers, contractors, sources, cooperating persons, financial institutions, transportation operators, critical-infrastructure partners, technical specialists, and temporary operational participants can support bounded functions. Their participation does not erase the distinctions among employment, authority, access, and mission. ## Relationships [[collections/Terrorism, Counterterrorism, and the Intelligence Environment|Collection landing page]] · [[wiki/Distributed Human-Sensor and Reporting Ecology|Distributed Human-Sensor and Reporting Ecology]] · [[wiki/Counterterrorism Collection - Fusion and Surveillance|Fusion and Surveillance]]