Introduction
Russia no longer relies solely on tanks, missiles, and overt coercion to exert influence in Europe. Instead, it has perfected a doctrine of sub-threshold operations—measures designed to weaken adversaries without crossing the line into formal war. These operations exploit the ambiguity between peace and conflict, allowing Moscow to advance strategic objectives while denying direct responsibility.
The Concept of the Grey Zone
The term “grey zone” captures the essence of sub-threshold activity. It describes a contested space where states conduct hostile actions below the threshold that would justify a military response. For Russia, this strategy is particularly effective against NATO and the EU, whose decision-making structures are slow, consensus-based, and cautious when escalation risks are present. The Kremlin calculates that its adversaries will tolerate constant irritation rather than risk all-out confrontation.
Disinformation and Influence Networks
Russian information warfare is the most visible manifestation of sub-threshold tactics. State media, proxy outlets, and social media networks spread disinformation narratives aimed at deepening social divides, undermining trust in democratic institutions, and normalising authoritarian perspectives. From fabricated stories about NATO biolabs to campaigns fuelling anti-migrant sentiment, the Kremlin has shown remarkable adaptability in exploiting Europe’s cultural fissures.

Cyber Operations and Infrastructure Sabotage
Beneath the surface, Moscow deploys cyber tools to probe, disrupt, and sometimes paralyse European systems. Attacks on parliaments, electoral commissions, hospitals, and transport networks show how digital infrastructure has become the new front line. Unlike bombs, cyberattacks allow Russia to strike repeatedly while maintaining plausible deniability. Technical attribution is slow, public messaging is muddled, and political leaders hesitate to escalate—a perfect environment for Moscow’s playbook.
Economic and Political Levers
Energy remains a central weapon. Even after the full-scale invasion of Ukraine in 2022, Russia continues to manipulate gas flows, leverage its role in global commodity markets, and cultivate business elites across Europe. Sub-threshold operations also include covert financing of political parties, support for extremist groups, and the use of corruption as a tool to bind decision-makers to Moscow’s interests. These mechanisms entrench influence without the visibility of military manoeuvres.

Hybrid Coercion and the Future of Conflict
The Kremlin’s sub-threshold strategy demonstrates that modern conflict is no longer defined by open declarations of war. Instead, Europe faces an adversary skilled at blurring the line between peace and hostility. By the time an operation is publicly acknowledged, the damage is already done. Unless Europe learns to recognise, attribute, and respond collectively, Russia will continue exploiting this grey zone to undermine sovereignty and stability from within.
Further Reading
The Kremlin Playbook: Understanding Russian Influence in Europe
Published by the Centre for the Study of Democracy (CSD), this landmark report details how the Kremlin exploits corruption, economic leverage, and political networks to entrench its influence across Europe. It remains essential reading for understanding the mechanics of Russia’s sub-threshold operations.