The Arctic Security and Diplomacy Act responds to growing concerns about espionage, military expansion, and influence operations by Russia and China in the Arctic region, including through supposedly civilian marine research activities that may have dual-use military applications like seabed mapping and undersea infrastructure surveillance. The bill requires the Secretary of State, working with intelligence agencies and the Department of Homeland Security, to develop a strategy within 180 days to identify and counter foreign espionage in the Arctic, and to produce a broader report within one year assessing these threats and recommending countermeasures, including the feasibility of an Arctic intelligence-sharing network with allied nations like Canada, Denmark, Norway, Finland, Sweden, and Iceland. A central provision requires foreign vessels to obtain U.S. government pre-approval before conducting marine scientific research in U.S. waters, and it bars approval for vessels linked to designated foreign adversaries—China, Russia, Iran, and North Korea—unless the Secretary of State grants a national interest waiver, which must be reported to Congress within five days. The legislation also directs U.S. diplomatic efforts, including sanctions, public condemnations, and coordinated pressure with allies, to enforce these restrictions and protect Arctic sovereignty, while emphasizing continued U.S. participation in the Arctic Council. This bill primarily affects the State Department, intelligence community, Homeland Security officials, foreign research vessels operating near U.S. Arctic waters, and Arctic allied nations, with most repor