Security policy refers to policy matters involving both national security and homeland security. It looks at the key substantive areas within national security policy and to review two important procedural aspects: the structure of the organizations created to support the executive branch and the rules involving classified information. Turning to the law and policy regulating intelligence, the first major statute enacted was the National Security Act of 1947. The law created the Central Intelligence Agency (CIA) and instituted an absolute prohibition on the CIA exerting any law enforcement or security functions inside the United States. The complexity of the modern world advances in technology, the rise of terrorism, and changes in communication have altered the way security policy is developed and expanded the area of focus beyond simply preservation of the United States and its sphere of influence.