The modalities through which states coerce have varied greatly across time and space shaped not just by the available instruments but also by prevailing norms of interstate behaviour. Gunboat diplomacy was part and parcel of the statecraft of Western seafaring states since the late Middle Ages, if not earlier. Its use became circumscribed by international law in the aftermath of the Second World War, diminishing although certainly not eliminating its salience as a tool of coercion. Coercion has thus evolved adapting to opportunities and limitations afforded by the Age. State-sanctioned privateering to intercept shipping of silver from the Americas to Europe, for instance, was a common practice in the seventeenth and eighteenth centuries. Attempts to control sea lines of communications in order to choke off trade flows were quite prevalent, both in peacetime and wartime, in the nineteenth and even twentieth centuries. Today, curtailing access to critical technologies and denying entry into the digital arteries of global finance – i.e., SWIFT – has become a recourse of choice.

Although the data on coercive state behaviour across different domains (e.g., military, economic, cyber) is scattered, it is undeniable that interstate coercion has been on the uptick since the 2010s yet with remarkable regional variation across countries and continents. European states have increasingly resorted to economic and financial sanctions combined with arms supplies to put direct and direct pressure on opponents, as they did in response to Russia’s invasion of Ukraine. The US has relied on a mixture of military, economic, financial, and cyber measures to coerce other states, such as pressuring Iran into negotiations over its nuclear programme, or China as part of a competition over global economic, technological, and military pre-eminence. Middle Eastern states have employed cyber-attacks below the threshold of armed violence in combination with economic boycotts, as Gulf states have done against Qatar, and Israel and Iran are engaged in a prolonged conflict involving cyber-operations, targeted killings, and attacks on military and economic assets. China and Russia, for their part, have both made use of a wide range of military and non-military levers – overtly and covertly – to pressure both their neighbours and rivals. Examples range from aerial intrusions of airspaces and cyber intrusions of critical infrastructures to persistent meddling in democratic elections and targeted killings to land reclamation projects and land grabs creating new faits accomplis on the ground. And states are not the only coercive actors. International organisations – both intergovernmental and supranational – have leveraged diplomatic, military, economic, and other non-military tools for coercive purposes, as attested by the EU and NATO’s response to Russia’s invasion of Ukraine.