There are places where geopolitics fades, where you can shut yourself off from the slow-burning conflicts and tumultuous markets, from the rise and fall of great powers. The Cook Islands are one such location. This grouping of 15 islands at the heart of the South Pacific is a tiny segment of a sweeping arc that sprawls across the Pacific from the Marianas to Polynesia. Some (such as New Guinea and New Zealand) are massive, while others are nothing more than the faintest ring of coral above blue water....