Climate models project that the Central Arctic Ocean (CAO) may soon become ice-free in summer for a limited window of time, opening a seasonally navigable route that connects Asia to Europe by crossing over the North Pole. This Transpolar Sea Route (TSR) and its surrounding waters in the CAO have seen little activity and would be available for seasonal commercial and surface military activity, particularly from the surrounding exclusive economic zones (EEZs) of Canada, Denmark (through Greenland and the Faroe Islands), Norway, Russia, and the United States. In this report, the authors explore how global actors may leverage new maritime access in the CAO for economic, political, and military gain. Drawing on insights from climate models, literature, and expert interviews, they examine current and potential future maritime uses of the ocean and the TSR by Arctic states and other actors. They then present a scenario in four phases of how these activities could plausibly develop in the CAO over time. The authors find that the most plausible scenario for maritime use of the CAO in the next 25 years is one of limited activity, though numerous factors could lead to expanded commercial and military presence by global actors.

The United States' use of instruments of national power is often constrained by a focus on diplomatic, informational, military, and economic approaches, with a strong emphasis on the military and diplomatic elements and typically less weight on informational and economic measures. However, the often-neglected financial, intelligence, and law enforcement elements of national power offer critical means for the United States and its allies and partners to meet strategic objectives in the Indo-Pacific, especially given China's frequent use of these approaches to subvert international norms. As the United States strives for a free and open Indo-Pacific, the foundations of international law need to be reinforced as the bedrock of global relationships. In particular, sustained enforcement of established maritime legal principles is the best approach that democratic societies can employ to reestablish the rule of law in the Indo-Pacific. This paper describes how a combined maritime force (CMF) of international coast guards and maritime law enforcement agencies, under the leadership of the U.S. Coast Guard, might institute a shared vision focused on the enforcement of maritime law and international norms. First, it discusses China's gray zone tactics and why such tactics call for a CMF. Next, it defines CMF and discusses the potential benefits of such a force. Then it explains in more detail what such a force would look like in terms of its focus areas, leadership, and membership. It concludes with a brief discussion of next steps.