Thirty years after the fall of the Berlin Wall, America and Russia have again returned to conflict. But this renewed confrontation did not come out of the blue. Rather, it was preceded by a long period of stagnation and a final crisis in the realm of arms control. In particular, the agreements of cooperative arms control in Europe eroded after the turn of the millennium. Why did that neatly established network of security agreements collapse? In this new volume, Ulrich Kühn traces the rise and fall of cooperative arms control in Europe from the early Helsinki days to the Russian annexation of the Crimea in 2014. In so doing, Kühn uncovers a regime complex that has so far remained unknown and that spans across various organisations, agreements, and institutions.