The Polar-Lunar Continuum: A Unified Framework for Extreme-Environment Infrastructure Investment

The Arctic Circle and the lunar south pole share six classes of structural constraint — energy scarcity, extreme-environment engineering requirements, autonomous systems dependency, capital intensity with long amortization timelines, governance sensitivity, and logistical vulnerability — that produce analogous economic behavior, though not at equal magnitude in each domain. Despite this structural similarity, U.S. policy treats these domains as separate investment problems, allocating through distinct agency budgets, regulatory frameworks, and program offices. China, by contrast, appears to operate across both domains through a unified developmental axis — the Polar Silk Road as proof of concept for lunar-scale extreme-environment industrialization (see Section 4 for the evidence and its limits). This paper proposes the **Polar-Lunar Continuum** as a research framework with two defining criteria: two domains form a unified geoeconomic theater when (1) they share the six structural constraints and (2) the same capital-allocation logic applies to both. These criteria are treated here as a stipulated definition, not as a proposition claimed to be derived or proved. We present evidence from Arctic infrastructure commitments, projected cislunar economy valuations, China's integrated Polar-Silk-to-lunar strategy, and U.S. institutional fragmentation. We propose an evaluation matrix for program officers and investors to score dual-domain applicability, and a case for an International Extreme-Environment Infrastructure Bank (IEEIB) as the institutional vehicle for unified investment.