Plain-language explanation.
International Relations (IR) is the study of interactions between states and other actors in the global system — war and peace, diplomacy, trade, international organisations, and global governance. It asks: why do states cooperate or conflict, and how is world order maintained or changed?
Core concepts and standard treatment.
Core IR covers the main theoretical paradigms: realism (states are primary actors, anarchic international system, power politics — security dilemma; Morgenthau — classical realism; Waltz — structural realism / neorealism — polarity; Mearsheimer — offensive realism — great power conflict; Carr — 'The Twenty Years' Crisis'), liberalism (cooperation is possible — international institutions reduce anarchy; Kant — perpetual peace — democracy, commerce, international law; Keohane — neoliberal institutionalism — complex interdependence; democratic peace theory — democracies rarely go to war with each other), and constructivism (international reality is socially constructed — Alexander Wendt 'Anarchy is what states make of it'; norms, identity, and ideas shape state behaviour; norm lifecycle — Finnemore and Sikkink). Key concepts: sovereignty (Westphalian — 1648; R2P — Responsibility to Protect), international law (UN Charter; ICJ; ICC; treaties; customary international law), and international organisations (UN — Security Council P5; NATO — collective defence Art. 5; WTO; IMF; World Bank).
Deeper theory, debates and edge cases.
Advanced IR covers critical theories (post-colonialism in IR — Fanon, Said's Orientalism applied to IR — Hobson; feminist IR — Enloe, Tickner — gendered analysis of war and security; Marxist IR — world-systems theory — Wallerstein — core-periphery — dependency theory — Frank, Cardoso; post-structuralist IR — Campbell — foreign policy as discourse production), security studies (traditional vs non-traditional security — Copenhagen School — Buzan — sectors of security — societal, environmental, economic; securitisation theory — speech acts; nuclear deterrence — MAD, extended deterrence — Schelling; hybrid warfare — Gerasimov doctrine; cyberwar — Tallinn Manual), and international political economy (IPE — hegemonic stability theory — Kindleberger, Gilpin; global value chains — Gereffi; financialisation of the global economy; trade wars — WTO dispute settlement; sanctions regimes — OFAC; Belt and Road Initiative — BRI — geopolitical implications).
How it is applied in practice.
At the diplomat, international affairs analyst, and think-tank researcher level, practitioners contribute to International Security, International Organization, and World Politics; advise foreign ministries and international organisations (UK FCO/FCDO; US State Department; EU EEAS; UN DPPA — peace operations); publish policy analysis for think tanks (IISS, Chatham House, Council on Foreign Relations, RAND Corporation, ECFR); lead conflict analysis and conflict resolution programmes (Uppsala Conflict Data Program — UCDP; ICG — International Crisis Group; Track II diplomacy — non-governmental dialogue); design and evaluate sanctions programmes (UN Security Council sanctions committees; OFAC SDN list; EU restrictive measures — their effectiveness and humanitarian impact); and contribute to international law practice (ICC prosecution; ICJ advisory opinions; UNCLOS arbitration — South China Sea; international criminal law — genocide, crimes against humanity — Rome Statute).