Free trade is, in one sense, like a nuclear weapon.
Which seems strange to say because trade is associated with peace and prosperity, while nuclear weapons are synonymous with apocalypse and terror. Trade, in a similar way, binds the fortunes of people in the world together. It is the best assurance of peace. With trade, a war abroad will have fallout at home. But while trade has the deterrent effects of powerful weapons, is far preferable because of its other advantages.