The struggle for a liberal world order transformations, learning processes and the global challenges of the long 20th century

This article reappraises the rise, impact and limitations of aspirations to create a rule-based liberal world order in the transformative ‘long’ 20th century (1860–2025). Pursuing a poly-perspectival and global approach, it illuminates dominant ideas and concepts that informed these aspirations. And it analyses how far those who became key actors in this process indeed found ways – against both authoritarian and communist competitors – to remake the norms, ground-rules and institutional foundations of international order on liberal premises, and on a truly global scale. Finally, it explores what lessons can be drawn from liberal achievements and frustrations of the long 20th century to rebuild a rule-based world order for the 21st.