Mr. Schleien was appointed Deputy Assistant Secretary of Defense for Arctic and Global Resilience in March 2025, with responsibilities for Arctic security, oceans-related issues, and strategic resources (including critical minerals).

Prior, Mr. Schleien was appointed Deputy Assistant Secretary of Defense for Russia, Ukraine, and Eurasia in December 2024, with the responsibility for policy concerning Russia, Ukraine, and Eurasia (Belarus, the Caucasus, Central Asia, and Moldova).

Starting in July 2022, Mr. Schleien was DASD for Defense Continuity and Mission Assurance (DC&MA).  In this position, Mr. Schleien was responsible for the development of plans, policies, and leadership support initiatives to assure the Department and the U.S. Government could ensure continuity of government, continuity of operations, and enduring constitutional government through all threats and hazards. DC&MA also strengthened DoD capabilities through its mission assurance process, increasing the capabilities of defense critical infrastructure to support the department’s operational plans. He was also responsible for domestic force protection policy.

From October 2015 to June 2022, Mr Schleien was OUSDP Chief Operating Officer, overseeing all organizational management and support functions, including budget, human resources, information technology, administrative services, facilities/operations and performance management. As COO, Mr. Schleien was the USDP's primary advisor and manager of these functions.

PAST EXPERIENCE: Mr. Schleien was Principal Director for Cyber Policy from June 2010 (following his tenure as Director for Cyber Policy starting in October 2009) until September 2012. He was responsible for strategy and policy development for DoD activities in the cyber domain, policy oversight of stand up of US Cyber Command, international cyber engagement, and interagency cyber relationships.

From 2007 through October 2009, Mr. Schleien was Director for Transnational Threats Policy (and Acting Principal Director for Combating WMD Policy from March 2009 through October 2009). He was responsible for WMD/missile-related interdiction and export control regimes; Proliferation Security Initiative (PSI); oceans policy ; cluster munitions policy; Nuclear Non-Proliferation Treaty (NPT); Trafficking in Persons sanctions process; and UN Conference on Disarmament.

From 1994 to 2007, Mr. Schleien held various positions in OUSD/Policy, including Deputy Director for Nonproliferation Policy, Senior Assistant for NATO Policy, Deputy Permanent Representative to the Organization for the Prohibition of Chemical Weapons (resident in The Hague, Netherlands), Senior Assistant for Nonproliferation Policy, and Deputy Director for Non-Nuclear Arms Control.

EDUCATION: Mr. Schleien earned a Master of Public Management in National Security Policy from the School of Public Affairs, University of Maryland, and a Bachelor's in Chemistry from Lafayette College. He attended the Federal Executive Institute in 2001.

Mr. Schleien has been awarded the Secretary of Defense Medal for Meritorious Civilian Service three times and the OSD Medal for Exceptional Civilian Service three times. He was appointed to Senior Executive Service in April 2010.