Ari Kalker, CEO
Sergeant Major (Res.) Ari Kalker is the Founder and CEO of the Joshua Institute, the first think tank dedicated exclusively to the academic study, policy development, and long-term advancement of Israel's lone soldier community. A New York native who made Aliyah in 2001, Ari is an IDF combat veteran who continues to serve in an active combat role well past the age of 40 as a team leader in the 6551 Reconnaissance Battalion, the reconnaissance unit of the 551 Reserve Brigade under Division 98. Since October 7, he has served more than 400 days across eight combat deployments in Gaza, Lebanon, Syria, and along Israel's eastern frontier. His commitment to service is deeply personal, inspired by a family legacy that includes an Auschwitz survivor, a World War II U.S. Navy veteran, and a namesake who was killed fighting as a Jewish partisan during the Holocaust.
Before founding the Joshua Institute, Ari played a leading role at the Lone Soldier Center in Memory of Michael Levin, where he established Jerusalem's first group housing projects for lone soldiers. In civilian life, he is a general contractor, building the city of Jerusalem while continuing to defend it in uniform. Through the Joshua Institute, Ari is working to transform how Israel understands and supports lone soldiers by producing rigorous research, developing national policy, strengthening cooperation across the sector, and cultivating the next generation of Israeli leadership rooted in service, responsibility, and national purpose.
HAim brenner, COO
Haim Brenner is the Chief Operating Officer of the Joshua Institute, where he leads the organization's day-to-day operations, strategic partnerships, and institutional development. A dual American-Israeli citizen who made Aliyah as a teenager, Haim is a combat veteran of the IDF's Paratroopers Reconnaissance Unit and continues to serve as a Master Sergeant (Res.) in the 6551 Reconnaissance Battalion, the reconnaissance unit of the 551 Reserve Brigade under Division 98. Since October 7, he has completed multiple combat deployments in Gaza, Judea and Samaria, and along Israel's northern front. He holds degrees in Business Administration and Middle Eastern and Islamic Studies from the Hebrew University of Jerusalem and has worked in national security, business development, and public policy. Through the Joshua Institute, Haim is focused on building the organization's research capabilities, strengthening collaboration across the lone soldier ecosystem, and translating rigorous data into practical policy that improves outcomes for lone soldiers, veterans, and the State of Israel.