Our Team
Decades of Experience
Phalanx Meridian is led by a multidisciplinary team with decades of combined experience operating across security, humanitarian, and strategic advisory domains in complex and austere environments. Our leadership brings a rare blend of regional expertise, operational discipline, and institutional insight developed through work with government agencies, international organizations, and multinational partners.
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Together, the team integrates strategy, operational governance, technical risk management, and on-the-ground execution to deliver reliable, adaptable solutions where conditions are uncertain and stakes are high. Guided by Phalanx Meridian’s mission, our leaders combine sound judgment with practical experience—providing clients with the confidence that programs, people, and operations are supported by teams who understand the realities on the ground.
Sean Osner
Founder & Chief Executive Officer
Sean Osner brings decades of leadership experience across peacekeeping operations, humanitarian engagements, and strategic development initiatives in the Middle East, West Africa, and the Caribbean. His work has consistently focused on operating within complex political, security, and socio-economic environments, where his analysis of local and regional dynamics informs policy decisions and operational strategies grounded in on-the-ground realities. Through sustained diplomatic engagement and senior advisory roles, Sean has contributed to addressing emerging security challenges while advancing stability, governance, and peace in fragile environments.
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As an international development professional, Sean has held senior leadership positions with the United States Agency for International Development (USAID), most recently serving as Deputy Director of the Office for Donor Coordination. His prior roles include Chief of Civilian Observers with the Multinational Force and Observers in Sinai, Egypt; Director of the Program Resource Management Office in USAID/Mali; Director of the Democracy, Human Rights, and Governance Office in USAID/Jordan; and USAID Representative to Niger from 2013 to 2015. Earlier in his career, Sean served with the United Nations Volunteers Programme in Egypt and as UN Volunteers Coordinator in Jordan and Lebanon.
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Sean’s background also includes military service including assignments with the U.S. Army’s 7th Infantry Division and the U.S. Military Academy Preparatory School. He is fluent in Arabic and French, with working proficiency in Spanish, Italian, Bambara, and Hebrew. Outside of his professional work, Sean maintains a strong commitment to personal fitness and is an avid freediver and PADI-certified Assistant Dive Instructor.
Nathan Wagner
Chief of Staff
Nathan Wagner is an operations, planning, and technical advisory professional with experience supporting complex missions across security, humanitarian, and government-adjacent environments. His background combines analytical rigor, operational coordination, and disciplined execution, with a focus on enabling decision-makers through clear planning, accurate reporting, and practical problem-solving.
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Nathan has worked across interagency, multinational, and civilian-military contexts, supporting operational planning, data analysis, logistics coordination, and technical reporting in dynamic and time-sensitive environments. His experience includes managing information flows within operations centers, supporting field missions, coordinating with local and international stakeholders, and translating complex technical and operational data into actionable insights for leadership.
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Nathan brings a structured, methodical, and mission-focused approach to his work, emphasizing clarity, accountability, and adaptability. His strengths include operational analysis, planning support, stakeholder coordination, and the development of systems and processes that improve efficiency and decision-making in complex operational settings.
Scott Updike
Chief Technical Advisor
Matthew “Scott” Updike is Chief Technical Advisor and co-owner of Phalanx Meridian, with 27 years of service in the United States Army, specializing in ground reconnaissance, cavalry, light infantry, and airborne operations. Scott has operated and advised at the tactical, operational, and strategic levels across combat deployments, international affairs, peace treaty observation missions, and humanitarian operations throughout the Middle East and Europe.
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Scott brings deep expertise in risk assessment, operational planning, and small-team leadership in complex, austere, and politically sensitive environments. He has a proven ability to advise senior leaders, support interagency and multinational coordination, and operate within strict compliance, discretion, and mission-focused frameworks.
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Scott applies military and international operational experience to civilian advisory roles, supporting government and institutional partners with disciplined, scalable, and results-oriented solutions. His core strengths include strategic advising, operational oversight, personnel utilization, and cross-cultural engagement in high-risk and emerging environments.