Are Embassies Still Spy Bases?

Are Embassies Still Spy Bases?

The Thin Line Between Diplomacy and Espionage

Introduction

A spy, defined in Hague Convention 1899 & 1907 in Article 29 as a person who secretly or under false pretenses gathers information in a war zone for a belligerent state (Hague Convention IV, 1907, art. 29). Since the earliest formations of statecraft, the boundaries between diplomacy and intelligence have remained blurred. The codification of diplomatic norms under the Vienna Convention on Diplomatic Relations (1961) granted protections that, paradoxically, have been systematically exploited by intelligence agencies throughout the twentieth and twenty-first centuries. Though earlier international legal frameworks emerged, envoys and diplomats were always welcomed by the host state with extraordinary protections because of the sense of respect against diplomatic mission and expectation of reciprocal behaviour. This was governed by customary law, though not written, but was unanimously followed and punished if not followed.

The Cold War marked institutionalisation, as embassies across major political capitals transformed into operational headquarters for agencies such as the CIA and KGB. Despite the dissolution of the Soviet Union in 1991, the intersection of diplomacy and espionage has not diminished; rather, it has evolved in response to shifting asymmetric threats and technological advancements. This paper argues that the relationship between diplomacy and intelligence is not incidental but structurally embedded within the practice of statecraft, and while the methods and legal frameworks have evolved across historical periods, the fundamental function of diplomatic missions as intelligence-gathering platforms has remained a consistent and defining feature of competition.

A Shared History

In the ancient Near East, Egypt, Persia, Greece, and Rome regularly dispatched envoys not only to negotiate alliances and treaties, but also to gather political and military intelligence about rival states. In ancient Greece, particularly during the Peloponnesian War, emissaries and merchants acted as informal intelligence agents, carrying strategic information between city-states (Mattingly, 1955). During the Byzantine Empire, diplomacy became even more closely connected with espionage. Byzantine diplomats were trained to collect information regarding foreign courts, military capacities, and political rivalries while simultaneously spreading misinformation and influencing alliances (Shepard, 1998).

The diplomacy of the Italian Renaissance was largely driven by commerce, with many diplomats also serving as bankers and merchants. In an era without newspapers, these diplomats became essential intelligence sources, reporting on cargo arrivals, court affairs, alliance statuses, military mobilizations, market conditions, and political rumors (Black, 2010).

The rise of centralized monarchies such as France, England, Austria, and Prussia transformed intelligence gathering into an essential instrument of statecraft. As competition over trade, strength, and alliances intensified, states began to establish permanent embassies to ensure constant access to reliable information. Their reports frequently contained information about troop movements, alliance negotiations, trade fluctuations, taxation, succession disputes, and even rumors circulating within royal courts. Hence, permanent embassies became centers for covert activities.

The invention of the telegraph, radio communication, and modern cryptography accelerated both diplomatic communication and intelligence gathering, especially prior to the First World War, where espionage became industrialized and closely integrated with military operations. Governments employed military attachés stationed at embassies abroad, whose official purpose was to observe military ceremonies and maintain relations with foreign armed forces. Neutral embassies often became meeting points for spies, intermediaries, and secret negotiations (Keegan, 2003).

The interwar period and the rise of totalitarian regimes further intensified intelligence activities. Nazi Germany, Fascist Italy, and the Soviet Union developed extensive diplomatic missions abroad that often functioned simultaneously as centers of intelligence coordination and propaganda dissemination. During the Second World War, embassies in neutral countries became critical centers for espionage, secret negotiations, and prisoner exchanges. The United States expanded intelligence facilities by forming the Office of Strategic Services (OSS), later to become the CIA, institutionalizing the relationship between diplomacy and intelligence during wartime.

The Cold War marked the ultimate espionage and intelligence competition. The global struggle between the United States and the Soviet Union emerged through proxy wars, propaganda, covert operations, and technological surveillance. American CIA and Soviet KGB activities expanded in the domain of diplomacy, transforming traditional diplomatic missions. Intelligence officers working under diplomatic immunity could gather sensitive political, military, and economic information while minimizing the risk of prosecution. Diplomats and intelligence officers constantly sought to recruit scientists, military personnel, and politicians as informants.

The KGB extensively used its embassies as intelligence headquarters abroad, where diplomats frequently maintained close operational coordination with intelligence officers responsible for surveillance, disinformation campaigns, and the recruitment of foreign agents. Furthermore, diplomatic pouches, protected under international law from inspection by host states, served as tools for secretly transporting classified documents, surveillance equipment, and codes.

Diplomatic Cover

Intelligence officers frequently operated under diplomatic cover by serving as political attachés, cultural representatives, military attachés, or embassy staff. The legal foundation for diplomatic immunity was codified through the Vienna Convention on Diplomatic Relations 1961 under the framework of the United Nations. The convention formally established the inviolability of embassies, immunity from arrest and prosecution, and protection of diplomatic correspondence and pouches from inspection by host governments. Article 41 prohibits diplomats from interfering in the internal affairs of host states, but rather than prosecuting diplomats suspected of espionage, states most usually declare individuals persona non grata and expel them.

One of the most significant Cold War espionage networks was the Cambridge Five, recruited by Soviet intelligence while studying at Cambridge University. Maclean was working at the British Embassy in Washington and supplied nuclear and diplomatic secrets to the Soviet Union, while Kim Philby served as liaison between British intelligence and the CIA before being exposed as a Soviet double agent (Reuters, 2025).

In 1971, the British government launched Operation FOOT, expelling 105 Soviet officials from the Embassy of the Soviet Union in London, concluding that many were KGB and GRU intelligence officers operating under diplomatic cover (Hughes, 2006).

The most famous example of a diplomatic crisis on alleged espionage is the Iran Hostage Crisis, in which Iranian revolutionaries seized the US Embassy in Tehran, accusing American diplomats of conducting espionage through diplomatic cover. Documents recovered were publicly used by the Iranian government as evidence of intelligence activities and covert political involvement in Iranian affairs (National Archives, n.d.).

The attacks of September 11, 2001, resulted in a major transformation of the international intelligence structure. The United States expanded agency authority through the USA PATRIOT Act, and intelligence alliances such as the Five Eyes partnership deepened cooperation in surveillance and information sharing. In 2013, Edward Snowden disclosed classified information regarding global surveillance programs, revealing monitoring of allied leaders and diplomatic missions. The disclosures generated significant diplomatic tensions, particularly after allegations that Chancellor Angela Merkel's communications had been monitored, demonstrating that even allied states engaged in espionage against one another.

Russian Embassies and Espionage in Europe

Several Russian intelligence agencies are responsible for gathering information abroad, with the Foreign Intelligence Service (SVR) and the Main Intelligence Directorate (GRU) being the most prominent. The SVR conducts espionage and manages foreign missions, while the GRU addresses national security and military affairs both domestically and internationally (Dejene, 2024).

The 2018 Skripal poisoning in Salisbury marked a turning point, changing how Western nations view Russian diplomatic missions (Borger et al., 2018). Western intelligence agencies determined that Russian embassies often serve as operational centers, using diplomatic immunity to protect undeclared intelligence officers who collect information, map critical infrastructure, and coordinate logistics (Conley & Gabidullina, 2021). The expulsion of over 100 Russian diplomats significantly disrupted these espionage networks.

The 2021 Vrbětice incident highlighted the close connection between Russia's diplomatic presence and its intelligence activities in Europe. Czech intelligence conclusively linked Unit 29155 of Russia's GRU to the fatal 2014 ammunition depot explosion in Vrbětice. In response, the Czech government expelled 18 Russian embassy staff members identified as undercover GRU and SVR operatives (Lopatka, 2021), bringing to light the Kremlin's use of its Prague embassy to facilitate subversive activities and shield state-sponsored saboteurs.

Following Russia's 2022 invasion of Ukraine, European states dramatically escalated security measures, expelling hundreds of Russian officials and dismantling embassy surveillance equipment. By November 2022, according to British Security Service director Ken McCallum, over 600 Russian diplomats — 400 identified as spies — had been expelled (Terrero Carrobles, 2025). In response, Russia intensified its clandestine activities and restructured GRU units, including the newly formed Unit 54654 (Dejene, 2024). This operational shift became especially evident during the 2024 European Parliament elections, when intelligence agencies exposed the Voice of Europe network, a Kremlin-backed front that funnelled cash and cryptocurrency to far-right candidates. During late 2024 elections in Moldova and Romania, Russian intelligence orchestrated coordinated vote-buying schemes and illicitly funded TikTok bot networks, prompting Romanian courts to annul a presidential election round (Bryjka, 2024; Tejeda, 2024).

Conclusion

The role of diplomacy in the field of intelligence has been inherited from the earliest times of statecraft and is still actively applied today. What changes across centuries is not the intention, but the sophistication of the methods and the legal architecture constructed around them. This paper has argued that the relationship between diplomatic institutions and state intelligence is not incidental or opportunistic, but structurally embedded in the very logic of statecraft.

The Vienna Convention of 1961 formalised the conditions that made it more exploitable. The immunities and inviolabilities designed to protect diplomatic function became, in practice, the operational infrastructure of intelligence agencies worldwide. International law offers no uniform framework for prosecuting state-sponsored espionage conducted through diplomatic cover. The persona non grata mechanism remains the primary tool available to host states — one that leaves the underlying practice intact.

The case in the contemporary European theatre reveals that what the mass expulsions since 2018 demonstrated was not that Russia had uniquely violated the spirit of diplomatic norms, but that it had done so more recklessly, more violently, and with less regard for maintaining the pretence that other states depend upon. As hybrid warfare, cyber operations, and influence campaigns increasingly blur the line between diplomatic activity and hostile state action, closing the gap between international law and international relations as practiced would require states to legislate honestly against their own most valued interests.

References

Black, J. (2010). A history of diplomacy. Reaktion Books.

Borger, J., Wintour, P., & Stewart, H. (2018). Western allies expel scores of Russian diplomats over Skripal attack. The Guardian. https://www.theguardian.com/uk-news/2018/mar/26/four-eu-states-set-to-expel-russian-diplomats-over-skripal-attack

Bryjka, F. (2024). Russian interference nearly overwhelmed Moldovan presidential election-referendum vote. PISM (Polski Instytut Spraw Międzynarodowych). https://pism.pl/publications/russian-interference-nearly-overwhelmed-moldovan-presidential-election-referendum-vote

Central Intelligence Agency. (2013, May 21). The real story of Argo. CIA. https://www.cia.gov/stories/story/argo/

Conley, H. A., & Gabidullina, R. (2021). The costs of weaponizing Russian and western diplomatic expulsions. Center for Strategic and International Studies. https://www.csis.org/analysis/costs-weaponizing-russian-and-western-diplomatic-expulsions

Gabidullina, R., & Morcos, P. (2022). Curtailing Russia: Diplomatic expulsions and the war in Ukraine. Center for Strategic and International Studies. https://www.csis.org/analysis/curtailing-russia-diplomatic-expulsions-and-war-ukraine

Geneva Convention Relative to the Protection of Civilian Persons in Time of War (Geneva Convention IV), Aug. 12, 1949, 75 U.N.T.S. 287.

Grey Dynamics. (2025). The silent hand: Russian intelligence activities in Europe. https://greydynamics.com/the-silent-hand-russian-intelligence-activities-in-europe/

Hague Convention (IV) Respecting the Laws and Customs of War on Land and Its Annex: Regulations Concerning the Laws and Customs of War on Land art. 29, Oct. 18, 1907, 36 Stat. 2277, 1 Bevans 631.

Hamilton, K., & Langhorne, R. (2011). The practice of diplomacy: Its evolution, theory and administration (2nd ed.). Routledge.

Hughes, G. (2006). 'Giving the Russians a bloody nose': Operation Foot and Soviet espionage in the United Kingdom, 1964–71. Cold War History, 6(2), 229–249. https://doi.org/10.1080/14682740600650235

Keegan, J. (2003). Intelligence in war: Knowledge of the enemy from Napoleon to Al-Qaeda. Alfred A. Knopf.

Lopatka, J. (2021). Czechs expel 18 Russian envoys, accuse Moscow over ammunition depot blast. Reuters. https://www.reuters.com/world/czechs-expel-russian-embassy-staff-pm-says-suspected-russian-link-ammunition-2021-04-17/

Mallett, M., & Shaw, C. (2012). The Italian Wars: 1494–1559: War, state and society in early modern Europe. Pearson.

Mattingly, G. (1955). Renaissance diplomacy. Dover Publications.

National Archives. (n.d.). 444 days: Selected records concerning the Iran hostage crisis 1979–1981. U.S. National Archives and Records Administration. https://www.archives.gov/research/foreign-policy/iran-hostage-crisis

Reuters. (2025). Newly released MI5 files detailed confessions from members of the Cambridge Five spy ring. https://www.reuters.com/world/uk/secret-uk-files-detailing-confessions-cambridge-five-spies-released-2025-01-14/

Shepard, J. (1998). Byzantine diplomacy, A.D. 800–1204: Means and ends. Variorum.

Tejeda, G. (2024). Romania's election nullified: Russian interference and the struggle for democracy. The Soufan Center. https://thesoufancenter.org/intelbrief-2024-december-13/

Terrero Carrobles, J. J. (2025). The shift in the Russian espionage's strategy in Europe (Opinion Paper No. 95/2025). Instituto Español de Estudios Estratégicos. https://www.defensa.gob.es/documents/2073105/2320887/cambio_de_estrategia_del_espionaje_ruso_2025_dieeeo95_eng.pdf/11b7713e-822e-7e49-6eb1-ea03015ccb7c?t=1762505702947

Vienna Convention on Diplomatic Relations, Apr. 18, 1961, 500 U.N.T.S. 95.