This post was originally published on GreenMet

Washington, DC – GreenMet, the nation’s leading accelerator for the development of reliable critical mineral supply chains, is leveraging its rapid growth by announcing the appointment of two former senior national security leaders to senior leadership positions on its Board of Directors. 

According to GreenMet CEO Drew Horn, “As GreenMet expands its reach and operations, the addition of Secretary Lisa Hershman as Board Chair and former CIA official Darrell Blocker as Vice Chair gives the company strong and experienced leadership as we enter the next level of growth.”   

Chairman Hon Lisa Hershman Vice Chairman Darrell Blocker

The Honorable Lisa Hershman is the former Chief Management Officer of the U.S. Department of Defense. As the third highest ranking official at the Pentagon, Hershman led operational reforms to a record-setting $37 billion in savings while also leading the more than $160 billion budget and 120,000 employees of the 28 Defense Agencies and Field Activities known informally as the Fourth Estate.  

Hershman has previously served in several senior corporate leadership roles and is the internationally published coauthor of Faster Cheaper Better with the late Dr. Michael Hammer. She earned her degree in engineering and industrial distribution from Clarkson University and has studied innovation with MIT / IMD and has received Executive Certificates in Finance from Cornell University, Board Governance from the Wharton School at Penn, and Management from the London School of Economics.  

After a distinguished career with the Central Intelligence Agency, Mr. Blocker currently serves as the Chief Operating Officer (COO) for MOSAIC Security, a strategic intelligence, crisis management and executive advisory firm. He retired after a successful 32-year career in the U.S. Intelligence Community earning the CIA’s Distinguished Career Intelligence Medal in 2018. He served four years as an Analyst/Briefer in the U.S. Air Force (1987-1990) and 28 years as a CIA operative (1990-2018).   

His CIA career highlights include serving as Chief of their iconic training facility, Deputy Director of the Counterterrorism Center, Chief of Africa Division, and multiple tours as a Chief of Station. At the time of his retirement, Darrell was the most senior black officer in the CIA’s Directorate of Operations with the rank equivalency of a three-star general.  

In addition to Hershman and Blocker, the Board of Directors continues to benefit from Directors Richard Blaksley, Bert Diaz, Arguiro Elefteriu, and George Sorial as well as Founder and CEO Drew Horn. Libra Group was an early supporter and investor in the work of GreenMet and continues to support GreenMet in many ways not the least of which is lending the talents of several of its staff to our Board of Directors (Blaksley, Diaz, Elefteriu)  

GreenMet is uniquely positioned to build capacity for the development of sustainable, reliable supply chains for rare earth and other critical minerals to meet North American energy and technology needs in support of our national security. Horn says, “The ability to tap domestic resources and process minerals onshore will ensure that the United States decides what and when critical minerals are deployed in our national defense and to protect our domestic economy, without fear of disruption by our adversaries.”  

“GreenMet is also extremely grateful to outgoing Chair Robert Seiden who led our corporate incubation for the first two years of operation. He and Stasia Kelly will remain involved in an advisory capacity. And many thanks to Manos Kouligkas for helping launch our vision and providing much needed encouragement as a startup company,” Horn said. “We have been and continue to be supported by visionaries and thought leaders who have sustained our efforts at all levels of development.” 


GreenMet ( is focused on developing the infrastructure for sustainable, reliable, and secure critical mineral supply chains to meet North American energy and technology needs. Based in Washington, D.C., GreenMet’s mission is to elevate the importance of responsible critical mineral mining, mineral processing, and metallurgy. The company works to promote domestic mineral resource development as integral to U.S. trade and defense, energy, and fiscal policy.

According to Executive Order 13817, “Critical Minerals” are defined as a non-fuel mineral or mineral material essential to the economic and national security of the United States, the supply chain of which is vulnerable to disruption, and that serves an essential function in the manufacturing of a product, the absence of which would have significant consequences for our economy or our national security.