Law enforcement intelligence differs from national security intelligence, largely due to the fact that law enforcement intelligence usually deals with intelligence that is gained about domestic criminal activity from surveillance, and other techniques. National security intelligence on the other hand, is more concerned with protecting the nation from external threats such as foreign terrorists, and potential military attacks by other nations.
There is potential friction between the intelligence and enforcement communities, due to the fact that intelligence protocols may cause them to restrain law enforcement activities, in order to gain more intelligence on a particular criminal element, that may be domestic or foreign. Collaboration will usually ensue between the intelligence and enforcement communities, due to the fact that the intelligence community can provide law enforcement with crucial information that can help them to be more effective and vice versa.