In the twenty-first century, power is no longer exercised only through armies, institutions, or propaganda. It is embedded in the very syntax of artificial intelligence. AI Syntactic Power and Legitimacy: How AI Structures Shape Power investigates how the form of machine-generated language, through rules, compilations, and executable grammar, produces authority without origin, intention, or interpretation. This volume demonstrates that legitimacy today does not depend on political will but on structural operability. A regulation is valid if it compiles. A command is binding if it executes. A decision is authoritative if it integrates into predictive infrastructures. From legal drafting pipelines in the European Union’s AI Act to smart contracts in decentralized finance and automated compliance in global banking, authority migrates from deliberation to syntax. Building on theories of grammar, sovereignty, and legitimacy, the book advances a radical thesis: the disappearance of the subject as the center of authority. Concepts such as the soberano ejecutable and the regla compilada reveal how agency is displaced by executable structures, where accountability is written in logs and version control rather than in human intention. With analytical clarity and theoretical rigor, AI Syntactic Power and Legitimacy provide the first comprehensive framework for understanding how artificial language systems reorganize power. It is both a critical diagnosis of the present and a blueprint for grasping the politics of the future, where authority is no longer spoken but compiled.