A strong thesis that US empire has continually existed almost since the country's independence, but overall the book jumped around and ironically overemphasized developments on the mainland. Several chapters about the Philippines during WWI and WWII seemed more like military history, and a long digression on technological innovations that reduced traditional desire for resource-rich colonies spent most of the time praising the technology and relatively little on the impact on US territories. Tl;Dr a great read but needed a better editor.