	Introduction

The United States is currently facing two key challenges related to the U.S. intercontinental ballistic missile (ICBM) force. The discussion about whether to modernize or replace the ICBM force is a significant part of the national debate about the future of U.S. nuclear weapons. The United States also continues to extend deterrence to allies and partner nations with a "credible U.S. 'nuclear umbrella.'" As President Obama noted in the 2010 Nuclear Posture Review Report, the threat of global nuclear war has become remote, but the risk of nuclear attack has increased. There are several issues for Congress. First, Congress may consider whether the current plans for the nuclear enterprise (consisting of leadership, people and things that work on the nuclear mission) are sufficient to address the problems within the ICBM force or whether there may be other ways to sustain the current force. Second, Congress may consider whether the United States should continue to deploy ICBMs in the future nuclear force structure, particularly in light of expected financial constraints. It may consider whether nuclear weapons modernization programs will compete with each other, or with conventional weapons programs, for scarce resources. Finally, Congress may question whether the United States can afford to forgo ICBM sustainment and modernization programs in an era of changing national security challenges. Current U.S. Nuclear Force Structure

The U.S. nuclear force is a "Triad" consisting of strategic ballistic missile submarines (SSBNs) that carry submarine-launched ballistic missiles (SLBMs), the land-based ICBM force, and long-range bomber aircraft. According to the Nuclear Posture Review, "strategic nuclear submarines and the SLBMs they carry represent the most survivable leg of the U.S. nuclear Triad." Congress will play a key role in determining the future of the GBSD.
Determining the future role of U.S. nuclear weapons within the U.S. national security strategy is currently a topic of much debate. Many senior leaders are determined to design a strategy that defines a new role for U.S. nuclear weapons and makes those weapons responsive and relevant in today's global threat environment. The current U.S. nuclear enterprise consists of a triad of options: Intercontinental Ballistic Missiles (ICBMs), Submarine Launched Ballistic Missiles (SLBMs), and long-range bombers. All three legs of the nuclear triad are aging, since they were largely built to counter the threat of the Soviet Union. Policymakers in Congress and the Executive Branch are now deciding whether to modernize or replace parts of each leg.
The Obama Administration's 2010 Nuclear Posture Review (NPR) outlines its approach to reducing nuclear dangers and pursuing the goal of a world without nuclear weapons, while simultaneously advancing broader U.S. security interests. In his April 2009 speech in Prague, President Obama highlighted the current nuclear dangers in the global environment and declared the United States will "seek the peace and security of a world without nuclear weapons." The Nuclear Posture Review provides the roadmap for implementing President Obama's agenda for reducing nuclear risks to the United States, U.S. allies and partners, and the international community.
This raises several issues for Congress particularly regarding the Triad's ICBM component. First, Congress may consider whether the current plans for the nuclear enterprise are sufficient to address the problems within the ICBM force or whether there may be other ways to sustain the current force. Second, Congress may consider whether the United States should continue to deploy ICBMs in the future nuclear force structure, particularly in light of expected financial constraints. It may consider whether nuclear weapons modernization programs will compete with each other, or with conventional weapons programs, for scarce resources. Finally, Congress may address questions about whether the United States can afford to forgo ICBM sustainment and modernization programs in an era of changing national security challenges.