Background: Severe hemorrhage simultaneously compromises circulating volume, hemostasis, red-cell oxygen-carrying capacity, and tissue oxygen delivery. Fresh whole blood can restore several of these functions and remains the biological reference for hemorrhagic shock resuscitation when promptly available. Military medicine and emergency medical services (EMS), however, increasingly face scenarios in which these functions require support before appropriate blood products and surgical care can reach the patient. Objective: This Perspective examines the transition from unit-based blood replacement toward function-based resuscitation, with particular attention to prolonged casualty care, contested evacuation, drone-dominated warfare, strategic blood readiness, hemostatic technologies, oxygen-delivery therapeutics, and fieldable delivery systems. Evidence framework: Peer-reviewed military, trauma, transfusion, and oxygen-carrier literature was considered alongside Joint Trauma System guidance and official U.S. Department of Defense, U.S. Army, NATO, DARPA, FDA, Congressional, and Government Accountability Office documents. This is a narrative and translational Perspective, not a systematic review. Perspective: During the twentieth century, military trauma systems progressively compressed injury-to-surgical-care intervals from approximately 6-12 hours during World War II to 2-4 hours in Korea and approximately one hour during Vietnam [3]. During Afghanistan, implementation of the U.S. Department of Defense Golden Hour policy reduced median helicopter transport time in a large cohort from 90 to 43 minutes [6]. The operational assumption is now being challenged. Contemporary large-scale combat operation planning anticipates delayed or denied evacuation [10-17]. Ukrainian experience documents prolonged casualty care lasting 24 hours to multiple days, while drone saturation has displaced evacuation and surgical nodes farther from the contact line and increased the proportion of casualties arriving after prolonged intervals [10,11]. NATO has described the emerging transition from the “Golden Hour” toward a “Golden Day” in drone-contested environments [12]. U.S. requirements extend further: current Army planning discusses a 72-hour expectation, U.S. Marine Corps standards include capability beyond 96 hours for selected personnel, and USSOCOM research requirements seek far-forward solutions capable of supporting 3-5 patients for at least 5-7 days [13,16,17]. These changes redefine the engineering problem. The objective is no longer solely to move casualties rapidly toward advanced medical capability. Increasingly, therapeutic capability must move toward the casualty, remain available during prolonged holding and transport, and function with minimal infrastructure, personnel burden, weight, volume, and cold-chain dependence. Military medical research increasingly reflects this functional architecture. DARPA’s FSHARP program separated critical blood functions including oxygen delivery, hemostasis, and volume support [29]. Its 2026 RAPIID program explicitly advances “shelf-stable” oxygen carriers, platelet-derived products, and dried plasma toward clinical trials, regulatory authorization, scale manufacturing, and field deployment [31]. DARPA’s GOLDEVAC program independently explores automated prolonged resuscitation and oxygenation through a single intravascular interface extending from near the point of injury through evacuation [30]. Authors’ perspective: Next-generation far-forward oxygen therapeutics should be evaluated by both molecular oxygen-carrying performance and operational delivery architecture: shelf stability, compact form factor, minimal preparation, closed delivery, monitored administration, compatibility with clinically practical vascular access, flexibility during transport, and limited dependence on gravity-fed infusion systems. Within this framework, BHOC (Biological Hemoglobin Oxygen Carrier) is proposed as a candidate component of Precision Oxygen Therapeutics. Its intended function is oxygen transport and delivery under defined conditions, rather than replacement of the broader functions of whole blood. A proposed BHOC treatment protocol would pair a characterized biological oxygen carrier with a compact cartridge-based, controlled-delivery system. This concept requires independent physicochemical, engineering, preclinical, regulatory, and clinical validation. Conclusion: The central scientific question is changing from “How do we replace blood?” to “Which biological function is failing, how long must that function be supported, and how can it reach the point of casualty before appropriate definitive blood therapy becomes available?” This transition may define the next phase of military resuscitation, civilian EMS, and Precision Oxygen Therapeutics.