When U.S. President Barack Obama cancelled a scheduled September 2013 summit meeting with his Russian counterpart, Vladimir Putin, "lack of progress on issues such as missile defense" was cited as the primary justification. Despite widespread and well founded assumption that the real trigger for the cancellation was the Russian decision to offer temporary asylum to Edward Snowden, the citing of missile defense was indicative. The comment marked one of the periodic plateaus of mutual frustration between the United States and Russia over U.S. attitudes to missile defense capability, stemming from a continued failure to achieve meaningful dialogue over U.S. plans and Russian fears. Russia's vehement objections to U.S. plans for missile defense installations in Europe, and the range of unfriendly actions promised in response, are often portrayed as irrational, the arguments technically flawed, the behavior deliberately obstructive, and the underlying threat perception hopelessly out of date. Yet an examination of the missile defense relationship between Russia and the United States over time shows that the fundamental Russian concerns stem from ideas of state security which, while discounted elsewhere, remain valid in the Russian security calculus. The fundamentally different weight and importance attached by Russia to nuclear weapons as both a guarantee and a symbol of statehood can be challenging for U.S. observers to grasp, but it is critical to understanding those Russian statements that do not, at first sight, make rational sense to U.S. policymakers. Furthermore, while the current Russian proposals for compromise-at least those stated in public-are wholly unrealistic, bear in mind that some of the security considerations behind them, at various times, have been both shared and voiced by the United States. This book will examine the historical precedents for the current missile defense impasse, in order to explain the Russian attitude, and draw conclusions about both the most recent developments in the conversation between the United States and Russia and its likely further progress and prospects, if any, for a resolution.