Contact Us

News & Perspectives

The Espionage Threat to Military Exercises

Military organizations around the world routinely participate large-scale exercises in order to achieve a variety of objectives, making exercises highly appealing targets for espionage collection by adversaries. Moreover, some countries may conduct low-level collection activities against fellow participants. This paper will provide a brief overview of military exercises and the potential for associated intelligence collection activities. Additionally, this paper will examine case studies involving three (3) major exercises through the lens of espionage threats.

Military Exercises and the Espionage Threat
Per the U.S. Department of Defense (DoD), exercises are defined as “a military maneuver or simulated wartime operation involving planning, preparation, and execution that is carried out for the purpose of training and evaluation.” Some objectives of exercises may include testing new systems/capabilities, training personnel, strengthening alliances, testing interoperability with allies, and geopolitical signaling to adversaries.1

Adversaries may seek to collect against exercises to better understand their likely opponents in the event of conflict. Exercises may reveal valuable insights such as the operational structures, strategy/tactics, and equipment utilization of opposing militaries. Adversaries may deploy technologically-advanced assets such as spy ships, aircraft, and satellites in order to successfully collect this intelligence. In turn, participation in exercises could create opportunities for participants to collect against one another. Such collection activities may include more overt forms of collection such as elicitation or unauthorized photography/videography. However, it is likely that any such activity occurs in a low-level fashion, in order to gain insights without jeopardizing crucial alliances.

Large-scale exercises frequently involve joint forces (incorporating ground, air, and naval units), as well as integration of multinational partners. Exercises can also serve as a useful platform to test new or emerging technologies in a simulated operational environment. The presence of these platforms (which could include stealth technology, unmanned systems, or advanced radars) likely draw the attention of adversaries and friendly collectors alike.

Case Study: RIMPAC
Rim of the Pacific (RIMPAC) is the world’s largest international maritime exercise, bolstering relationships among dozens of participating countries to safeguard sea lanes and secure the world’s oceans. Shortly after its founding in 1971, RIMPAC became a biennial exercise in 1974 due to its expanding scale. Hosted by the U.S. Pacific Fleet, RIMPAC’s 28th exercise (2022) in and around the Hawaiian Islands and Southern California included 26 nations, 38 surface ships, three (3) submarines, nine (9) national land forces, more than 30 unmanned systems, about 170 aircraft, and over 25,000 personnel. In late March 2024, personnel from 29 nations expected to participate in RIMPAC 2024 attended the final planning conference at Naval Base Point Loma Annex, San Diego. The 29th RIMPAC is expected to be executed in summer 2024.2,3,4

Reports over the past decade highlight potential intelligence surveillance activities by U.S. adversaries in the vicinity of RIMPAC activities. In 2014, China’s first time participating in RIMPAC, China sent an uninvited surveillance ship in addition to its four (4) People’s Liberation Army Navy (PLAN) ships. According to a spokesman for U.S. Pacific Fleet, China’s Dongdiao-class auxiliary general intelligence (AGI) ship (designed to collect electronic and communication data from nearby vessels and aircraft) operated within the U.S. Exclusive Economic Zone (EEZ) during the exercise. Some experts were confused with China’s decision to send an uninvited spy ship with other PLAN vessels participating in most levels of the operation; however, the former commander of U.S. Pacific Command viewed the move as a positive sign that the Chinese vessel operated within another country’s maritime zones according to international law. Two (2) years later, Russia also sent an AGI ship into international waters off Hawaii during RIMPAC 2016 after not receiving an invite due to its annexation of Crimea and aggression in Eastern Ukraine. In addition to the spy ship, the Russia destroyer Admiral Vinogradov (DD-572) shadowed the amphibious assault ship USS America (LHA-6) for two (2) days during the 2016 exercise.5,6,7,8

In 2018, the U.S. disinvited the PLAN from participating in RIMPAC 2018 in response to China’s militarization of the South China Sea. Nevertheless, U.S. Navy officials indicated that a PLAN AGI ship was spotted off the coast of Hawaii during RIMPAC 2018, causing no disruptions to the exercise. Given China’s continued military activities and the potential risks offering the PLAN to view American naval platforms, tactics, and capabilities up close, China has not been invited back as a RIMPAC participant since 2016.9,10,11

Case Study: Talisman Saber/Sabre
Talisman Saber (or Sabre) is a biennial military exercise held by the U.S. and Australia, along with a number of partner nations. The name of the exercise varies from year to year depending on which country leads the exercise (Saber for a U.S.-led exercise and Sabre for an Australian-led one). The 2023 iteration of the exercise included approximately 30,000 personnel from 13 countries, including regional first-time participants such as Papua New Guinea, Fiji, and Tonga. The exercise seeks to enhance cooperation among nations in the Indo-Pacific, particularly given increased threats from China.12,13

In the lead-up to the 2023 iteration of Talisman Sabre, a PLAN AGI ship was spotted approaching Australia and specific areas where the exercise was expected to be held. An Australian military officer stated that this type of activity has occurred since 2017. The vessel ultimately proceeded to just outside Australia’s territorial waters in order to monitor the exercise. An Australian maritime patrol plane made contact with the vessel, and the encounter occurred without incident. The same Australian military officer stated that “[China will] passively collect, and we’ll adjust” adding that ”there’s some things we don’t necessarily want to give away and we have methods of being able to employ our forces without giving those more sensitive aspects of our training away”.13,14

In addition to the AGI vessel, China reportedly utilized “hundreds” of its satellites to monitor the 2023 exercise. While open-source details regarding this activity are limited, satellites provide a platform to conduct collection of imagery and signals intelligence. Satellite imagery could reveal details about weapons systems, military formations, and logistics processes. Signal collection could potentially reveal information related to command and control, as well as information on communications, radar, and other systems that operate on the electromagnetic spectrum.15

Case Study: BALTOPS
Baltic Operations (BALTOPS) is an annual military exercise that is conducted in the Baltic Sea region. The exercise typically occurs once a year and has been held since 1972, which makes it one of the longest running multinational maritime exercises in the world. The timing and specific details of each BALTOPS exercise can vary slightly each year depending on logistical and operational considerations. However, participants generally expect the exercise to take place on a regular basis, providing an opportunity for North Atlantic Treaty Organization (NATO) allies and partner nations to enhance interoperability, strengthen defense capabilities, and demonstrate collective deterrence in the Baltic Sea.16

BALTOPS 23, which took place from 04 June-16 June 2023, comprised of 20 countries which was four (4) more than the previous year. The exercise was comprised of more than 6,000 personnel, including nearly 1,500 sailors, marines, and airmen which was more than twice as many as in 2020. 50 ships, and more than 45 aircraft from Belgium, Canada, Denmark, Estonia, Finland, and other NATO allies were able to train and conduct high-intensity defense activities to help enhance capabilities within the alliance. BALTOPS 23 was a significant exercise as it served as Finland’s first joint exercise since becoming a NATO member in April 2023.17,18

During BALTOPS 16 in 2016, two (2) Russian intelligence gathering ships were spotted shadowing U.S. Navy and NATO vessels. While the Russian vessels showed no signs of force or aggression, they came as close as 1 mile from NATO forces. With Russia invading Ukraine in 2022, BALTOPS has served as a major push in tightening the alliance within NATO. Russia almost certainly perceives increased NATO cooperation as a geopolitical threat, which in turn increases the appeal of the exercise as a target for intelligence collection activities.16,19

Large-scale military exercises will almost certainly continue to serve as highly appealing targets for intelligence collection. Adversaries will seek to collect on exercises in order to gain valuable insights into military capabilities that they may be likely to face in a conflict situation, while low-level collection may continue to occur among participants. RMC’s Intelligence & Climate Analysis Division continues to monitor relevant developments related to large-scale military exercises, to include potential espionage activities.


1. U.S. Department of Defense. (2017). DOD Dictionary of Military and Associated Terms. Retrieved from

2. U.S. 3rd Fleet Public Affairs. (2023, December 5). U.S. 3rd Fleet Hosts RIMPAC Mid-Planning Conference. Commander, U.S. Pacific Fleet. Retrieved from

3. U.S. 3rd Fleet Public Affairs. (2022, August 5). RIMPAC 2022 Concludes. Commander, U.S. Pacific Fleet. Retrieved from

4. Llanos, M. (2024, March 28). U.S. 3rd Fleet Hosts RIMPAC Final Planning Conference. Defense Visual Information Distribution Service. Retrieved from

5. LaGrone, S. (2014, July 18). China Sends Uninvited Spy Ship to RIMPAC. USNI News. Retrieved from

6. Harper, J. (2014, July 29). PACOM chief: China spying on RIMPAC brings ‘good news.’ Stars and Stripes. Retrieved from

7. LaGrone, S. (2016, July 06). Russian Spy Ship Now Off Hawaii, U.S. Navy Protecting ‘Critical Information.’ USNI News. Retrieved from

8. Eckstein, M. (2016, July 17). RIMPAC 2016: Russian Destroyer Shadowed USS America Near Hawaii. USNI News. Retrieved from

9. Eckstein, M. (2018, May 23). China Disinvited from Participating in 2018 RIMPAC Exercise. USNI News. Retrieved from

10. LaGrone, S. (2018, July 13). Navy: Chinese Spy Ship Monitoring RIMPAC Exercise, Again. USNI News. Retrieved from

11. Werner, B. (2018, May 24). China’s Past Participation in RIMPAC Didn’t Yield Intended Benefits of Easing Tensions. USNI News. Retrieved from

12. U.S. Department of Defense. (n.d.). Talisman Sabre 23 reflects U.S., allies’ commitment to Indo-Pacific.

13. McGuirk, R. (2023, July 21). US navy secretary says Australian multination military exercise demonstrates unity to China. AP News. Retrieved from

14. Greene, A. (2023, July 23). First image emerges of RAAF’s encounter with Chinese spy ship during Talisman Sabre. ABC News. Retrieved from

15. Hundreds of Chinese satellites spying on US-Australia military exercises. (2023, August 21). WION. Retrieved from

16. U.S. Navy. (2023, May 30). U.S. Sixth Fleet, Naval Striking and Support Forces NATO to Kick Off BALTOPS 2023. U.S. Navy. Retrieved from

17. Moore-Carrillo, J. (2023, June 16). US, NATO wrap up joint exercises in the Baltics, Europe’s High North. Military Times. Retrieved from

18. NATO. (2023, June 07). NATO ships participate in exercise BALTOPS 23. NATO. Retrieved from,T%C3%BCrkiye%2C%20the%20United%20Kingdom%2C%20and%20the%20United%20States..

19. Tomlinson, L. (2016, June 16). Russian Spy Ships ‘Shadowing’ US Navy During Large NATO Exercise, Navy Admiral Says. Fox News. Retrieved from

More RMC White Papers

Threat Primer: Hizballah

IntroductionIn early October 2023, the Palestinian political and militant group Hamas launched a large-scale attack into Israel from the Gaza...

Read More