What are the differences (similarities and differences) between the rights of the US Department of Homeland Security, the Department of Defense and the Federal Emergency Management Agency?

DHS, the Department of Homeland Security, was established after 9 1 1 to combat terrorism and ensure the security of American borders. Not only the intelligence agencies, but also the coast guard, customs and immigration are all under the Department of Homeland Security. ? The Federal Emergency Management Agency (FEMA) is equivalent to China's criminal police. It is aimed at crimes in the United States and abroad, but mainly at home. Of course, preventing terrorism also belongs to their scope of work, so it overlaps with the responsibilities of the CIA and the Department of Homeland Security. However, unlike the criminal police in China, anti-espionage is also the responsibility of the FBI. For example, spies who work for the United States leak American information to other countries or organizations.