Down:
1. tradecraft used to pass items or information between two individuals via a secret location - Dead Drop
2. activities aimed at protecting an organization or country from espionage, sabotage - Counterintelligence
3. collected from signal activities - SIGINT
4. where the U.S. National Security Agency (NSA) was founded - Fort Meade
6. gathered from human sources - HUMINT
7. codebreaking center during WWII - Bletchley Park
8. Israeli intelligence agency known for covert operations - Mossad
9. obtained from social media or other available sources - PAI
10. British Intelligence's deception plan to mislead the Germans about the Allied invasion target of Sicily during WWII - Operation Mincemeat
13. collected from satellite and aerial imagery - GEOINT
15. the Berlin Wall fell, marking the end of the - Cold War
16. Name of the Soviet Union launched the first artificial satellite, initiating the Space Race - Sputnik I
17. intelligence agency succeeding the KGB - FSB
18. the U.S. act that was enacted following the 9/11 attacks -  Patriot
21. involving the analysis of financial transactions - FININT