The Coldest War by Ian Tregillis

In an alternate twentieth century where secret wartime experiments produced ruthless clockwork soldiers, the uneasy peace after World War II gives way to a new, mechanized Cold War; the novel follows multiple viewpoint characters — operatives, scientists, and the engineered fighters themselves — as espionage, ideological rivalry, and personal vendettas collide, forcing harsh choices about freedom, loyalty, and what it means to be human in a world reshaped by invention and violence.

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