The title and the cover of this elegantly designed book are slightly misleading: The Senkaku, a group of uninhabited but bitterly contested islands in the East China Sea, is only an example of the major security problem the author – a renowned analyst of US security posture – is examining with the trademark scrutiny. The real problem for this future-oriented thoughtful research is calibrating the best response to a security test initiated by the fast-rising China or the slow-degenerating Russia in a location of their choice, where they have the advantage of proximity and initiative, while the USA has no direct stake but needs to provide support for an ally exposed to aggression. A swift Russian capture of Narva, which would not necessarily imperil the rest of Estonia, is the better-known example of this test, while a Chinese forceful move against Taiwan – one of O'Hanlon's cases – goes beyond the parameters of strictly limited and instantly successful use of overwhelming force. A Russian amphibious operation against the Norwegian Svalbard archipelago could have made a better example – and offered a different reference for the title, in which the word 'paradox' serves as a synonym to the perhaps over-used 'dilemma'. The author is more interested in the evolution of this test in the next 20 years than in its current outcomes, but the self-imposed restriction on the length of the text leaves only that much space for examination of possible development of key military technologies. One strong conclusion prescribes greater reliance on economic instruments for responding to, as well as preventing, probable pro-active hostile moves, even if the experience in enforcing sanctions is not that satisfactory.