This accelerating and widening circle of development
was only possible because the world economy grew more
open and integrated. At each stage, expanding trade was
a powerful driver of economic development – opening
up new markets, improving access to raw materials,
promoting international specialization and stimulating
technological diffusion and innovation – which in turn
drove further trade expansion.
A central challenge at each historical stage was the
development of international rules and structures capable of
helping countries to coordinate their increasingly international
economic interests, and of managing the powerful forces
and stresses unleashed by economic change, such as the
rise of new economic powers, the spread of technology
and production, and the deepening of global economic
integration. Periods of relative economic openness – after the mid-19th century, after 1945, and after the Cold War –
have tended to coincide with global economic development,
while periods of trade fragmentation and protectionism –
most notably during the inter-war period – have seen
economic development stall or go into reverse.