Matt Ridley, in The Rational Optimist, points to Voltaire’s and David Hume’s pointing out one of the timeless truths of international commerce — it makes the world safer:
Voltaire pointed out that people who would otherwise have tried to kill each other for worshipping the wrong god were civil when they met on the floor of the Exchange in London. David Hume thought commerce ‘rather favourable to liberty, and has a natural tendency to preserve, if not produce a free government’ and that ‘nothing is more favourable to the rise of politeness and learning, than a number of neighbouring and independent states, connected together by commerce and policy’.
.