I was really excited to learn there was any military history of the Pacific Northwest at all... then I read this book and discovered that 90% of it was the "Indian Wars" (more like slaughters) of the late 1800s. It is worth reading, but depressing to read. The most interesting part was the early age of European exploration of the Pacific Northwest... Spain came as far north as the Straits of San Juan de Fuca, and of course Great Britain had a presence. The final lines defining British Columbia, Washington State and Oregon were really the consequence of Britain negotiating from a position of weakness. The Pacific Northwest was very far from other British assets, and even the greatest naval empire couldn't reliably project power that far, to protect its commercial activities (predominantly the British Northwest Company- a fur-trading concern which was for a century second only to the British East India Company in profitability). American presence in the Northwest was steadily increasing, as the population came to the Oregon Territory, both overland and by water routes. By the 1860's, it was clear that the American population was going to so outstrip the British population in the region, there was no practical way the Crown could hope to rule the area. Giving in to the "54-40 or fight" was really the only option, unless Britain wanted to abandon the Northwest entirely.
The few Japanese attacks on the American mainland, in the form of submarine raids, were an historical curiosity, but of no real consequence, in the broader scope of the war.
Overall, it's probably the best (only?) book available on the subject. Overall, I found it dry in parts, and all the Indian Wars started to sound the same to me, but a reader more educated on the subject may disagree.