Scientific research on and projections of the changes taking place in the Arctic vary, but there is a general consensus that the Arctic is warming and sea ice is diminishing. Scientists at the U.S. National Snow and Ice Data Center reported that the annual Arctic minimum sea ice extent— which typically occurs in September each year—for 2014 was the sixth lowest in the satellite record and 479,000 square miles less than the 1981 to 2010 average (see fig. 1). Further, the 10 lowest September ice extents on satellite record have all occurred in the last 10 years. While much of the Arctic Ocean remains ice-covered for a majority of the year, most scientific estimates predict there will be an ice-diminished Arctic Ocean in the summer sometime in the next 20 to 40 years. These environmental changes in the Arctic are making maritime transit more feasible and are increasing the likelihood of further expansion of human activity including commercial shipping and oil and gas extraction. For example, most commercial ship activity in the U.S. Arctic is currently destinational—shipping into or out of the Arctic, mainly in support of commercial activity. However, melting ice could potentially increase the use of three trans-Arctic routes, the Northern Sea Route, Northwest Passage, and Transpolar Route, saving several thousands of miles and several days of sailing between major trading blocs. See figure 2 for locations of these shipping routes. Additionally, estimates of significant oil, gas, and mineral deposits in the Arctic have increased interest in exploration opportunities in the region. These resources include an estimated 13 percent of the world’s undiscovered oil, 30 percent of undiscovered gas, and some $1 trillion worth of minerals including gold, zinc, nickel, and platinum. Despite the changing climate and growing interest in the region, several enduring characteristics still provide challenges to surface navigation in the Arctic, including large amounts of winter ice and increased movement of ice from spring to fall. Increased movement of sea ice makes its location less predictable, a situation that is likely to increase the risk for ships to become trapped or damaged by ice impacts. Key strategic guidance details the United States’ national security objectives and shapes DOD’s and other stakeholders’ operations in the Arctic. The administration issued National Security Presidential Directive 66 in January 2009, which establishes U.S. policy with respect to the Arctic region and tasks senior officials, including the Secretaries of Defense and Homeland Security, with its implementation. This directive identifies specific U.S. national security and homeland security interests in the Arctic, including missile defense and early warning; deployment of sea and air systems for strategic sealift, maritime presence, and security operations; and ensuring freedom of navigation and overflight. To further the interests of the Arctic Region Policy, in May 2013 the president issued the National Strategy for the Arctic Region (National Strategy). This document articulates the administration’s strategic priorities for the Arctic region and includes lines of effort related to (1) advancing U.S. security interests, (2) pursuing responsible Arctic region stewardship, and (3) strengthening international cooperation. It prioritizes lines of effort for federal agencies and builds upon existing initiatives by federal, state, local, and tribal authorities; the private sector; and international partners. Additionally, the administration released the Implementation Plan for the National Strategy for the Arctic Region (Implementation Plan) in January 2014, which sets forth the methodology, process, and approach for executing the strategy, including a framework to guide federal activities in the region. Finally, since the Arctic region is primarily a maritime domain, existing U.S. strategic guidance relating to maritime areas continues to apply, such as National Presidential Directive 41 issued by the president in December 2004 and the National Ocean Policy Implementation Plan issued by the administration’s National Ocean Council in April 2013. DOD is responsible in the Arctic and elsewhere for securing the United States from direct attack, securing strategic access and retaining global freedom of action, strengthening existing and emerging alliances and partnerships, and establishing favorable security conditions. As the maritime component of DOD, the Department of the Navy has global leadership responsibilities to provide ready forces for current operations and contingency response that include the Arctic Ocean. Additionally, U.S. Northern Command has primary responsibility for advocating for Arctic capabilities due to the command having the only U.S. Arctic territory within its area of responsibility. In this role, Northern Command is responsible for collaborating with the relevant combatant commands, Joint Staff, services, and defense agencies to identify and prioritize emerging Arctic capability needs and requirements. U.S. European Command and U.S. Pacific Command also play a role by fostering collaborative working relationships with partners in the Arctic. Further, the North American Aerospace Defense Command provides aerospace warning and control and maritime warning in the Arctic and will continue to play a role in DOD’s ability to meet national security challenges in the region. Since the Arctic is primarily a maritime domain, the Coast Guard plays a significant role in Arctic policy implementation and enforcement. The Coast Guard is a multimission, maritime uniformed military service typically within the Department of Homeland Security that has responsibilities including maritime safety, security, environmental protection, and national defense, among other missions. Therefore, as more navigable ocean water emerges in the Arctic and human activity increases there, the Coast Guard will likely face expanding responsibilities in the region. In addition to DOD and the Coast Guard, a number of other federal departments and agencies, as well as interagency working groups, have Arctic responsibilities, ranging from scientific research to resource development, as shown in figure 3. Recent strategic guidance on the Arctic establishes a supporting role for DOD relative to other federal agencies, based on a low level of military threat expected in the region. However, DOD continues to monitor the security environment in the region and is tracking indicators that, depending on the outcomes, could change its threat assessment and affect the department’s future role. In January 2014, the administration issued its Implementation Plan for the National Strategy that outlines 36 activities and identifies the lead and supporting agencies responsible for each implementation activity. DOD was designated as a supporting agency for 22 of the 36 activities in the plan, such as activities related to supporting aviation requirements, led by the Federal Aviation Administration, and sustaining federal capability to conduct maritime operations in ice-impacted waters, led by DHS. DOD was designated as the lead agency for one activity: to develop a framework of observations and modeling to support forecasting and prediction of sea ice. We discuss ongoing actions related to this activity later in this report. Between the release of the National Strategy in May 2013 and the Implementation Plan in January 2014, DOD issued its Arctic Strategy in November 2013. The strategy establishes the department’s strategic approach to the Arctic and identifies the timeframes to be used for planning: near-term (present–2020), mid-term (2020–2030), and far-term (beyond 2030).The Arctic Strategy emphasizes that as sea ice diminishes and the Arctic opens to more activity, DOD may have an increased role supporting other federal agencies in the region. For example, DOD may support the Coast Guard in safety-related missions or the Federal Emergency Management Agency in disaster relief and mitigation efforts. The Arctic Strategy notes that DOD has seldom been tasked to execute these missions in the Arctic, but it may be asked to do more in the coming decades given the expected increase in activity in the region. DOD’s determination of its supporting role in the Arctic is based on its assessment of a low level of military threat in the region. The Arctic Strategy states, for example, that there is a willingness and an ability among the Arctic nations to manage and resolve disputes through an established international framework. This framework is based on a commitment between the five nations bordering the Arctic Ocean (the United States, Russia, Canada, Norway, and Denmark on behalf of Greenland) to the international legal framework governing the sea, and to the orderly settlement of any possible overlapping territorial claims. Also, the Arctic Council serves as a voluntary intergovernmental forum that provides a means for promoting cooperation, coordination, and interaction among stakeholders with interests in the region, although the Council omits matters related to military security. In 2014, we assessed U.S. involvement in the Arctic Council and provided recommendations to help clarify the direction of future U.S. participation and to position the United States for a successful Arctic Council chairmanship beginning in 2015. To further its supporting role in the Arctic, the Arctic Strategy states that DOD plans to continue to build interagency and international partnerships to meet security and defense commitments. The department currently participates in a number of activities intended to prevent conflict and enhance the region’s capability and capacity for multilateral security collaboration. For example, while the Arctic Council charter expressly omitted matters related to military security, DOD participates in a number of international forums focused on military security cooperation. This includes the Arctic Security Forces Roundtable, an annual collaborative forum cohosted by DOD and the Norwegian Ministry of Defence. This senior-level event is aimed at building confidence and encouraging discussion of the Arctic among the security forces of Arctic and non-Arctic nations. The most recent event was held in May 2015 and included representatives from 11 countries—seven Arctic nations, as well as France, Germany, the Netherlands, and the United Kingdom. Issues discussed, among others, included the effects of climate change on the region, search and rescue operations, and disaster relief. Additionally, DOD participates in the Northern Chiefs of Defense conference—a meeting among the defense leaders of the Arctic nations to discuss emerging security issues in the region and ways they can work together to address them. The most recent meeting was held in June 2013 and covered developing a common operating picture of the region; identifying each country’s roles, capabilities, and ability to deploy to the region; and identifying joint training opportunities. DOD also leads and is involved in a number of training exercises focused on the Arctic to build partner capacity in the region.