Today, free trade is often associated with right-wing free marketeers. In Pax Economica, historian Marc-William Palen shows that free trade and globalisation in fact have roots in nineteenth-century left-wing politics. In this counterhistory of an idea, Palen explores how, beginning in the 1840s, left-wing globalists became the leaders of the peace and anti-imperialist movements of their age. By the early twentieth century, an unlikely alliance of liberal radicals, socialist internationalists, feminists, and Christians envisioned free trade as essential for a prosperous and peaceful world order. Of course, this vision was at odds with the era' s strong predilections for nationalism, protectionism, geopolitical conflict, and colonial expansion. Palen reveals how, for some of its most radical left-wing adherents, free trade represented a hard-nosed critique of imperialism, militarism and war.

Palen shows that the anti-imperial component of free trade was a phenomenon that came to encompass the political left wing within the British, American, Spanish, German, Dutch, Belgian, Italian, Russian, French, and Japanese empires. The left-wing vision of a ' pax economica' evolved to include supranational regulation to maintain a peaceful free-trading system - which paved the way for a more liberal economic order after World War II and such institutions as the United Nations, the European Union, and the World Trade Organization. Palen' s findings upend how we think about globalisation, free trade, anti-imperialism, and peace. Rediscovering the left-wing history of globalism offers timely lessons for our own era of economic nationalism and geopolitical conflict.