Near the end of World War II, in an attempt to attack the United States mainland, Japan launched its fu-go campaign, deploying thousands of high-altitude hydrogen balloons armed with incendiary and high-explosive bombs designed to follow the westerly winds of the upper atmosphere and drift to the west coast of North America. After reaching the mainland, these fu-go, the Japanese hoped, would terrorize American citizens and ignite devastating forest fires across the western states, ultimately causing the United States to divert wartime resources to deal with the domestic crisis....