The overarching question imparting urgency to this exploration is: Can U.S.-Russian contention in cyberspace cause the two nuclear superpowers to stumble into war? In considering this question we were constantly reminded of recent comments by a prominent U.S. arms control expert: At least as dangerous as the risk of an actual cyberattack, he observed, is cyber operations’ “blurring of the line between peace and war.” Or, as Nye wrote, “in the cyber realm, the difference between a weapon and a non-weapon may come down to a single line of code, or simply the intent of a computer program’s user.”
John Tien is a Senior Fellow at the Harvard Kennedy School's Belfer Center for Science and International Affairs. From June 2021 to July 2023, he served as the Senate confirmed Deputy Secretary of the U.S. Department of Homeland Security (DHS), the third largest U.S. Federal Government Cabinet department consisting of over 260,000 people. In that role, he was the DHS Chief Operating Officer (COO) overseeing a budget of $105 billion and facilities in all fifty U.S. States and all territories as well as more than 3,000 personnel stationed overseas in more than 75 countries. Alongside the Secretary of Homeland Security, Deputy Secretary Tien led the policy development, operational oversight, and risk management of the Department’s statutory mission areas (and subordinate agencies) to include: cybersecurity and protection of America’s critical physical and cyber infrastructure (CISA); disaster preparedness and recovery (FEMA); supply chain optimization, border security, and free and fair trade (CBP and ICE); air, pipeline, and rail security (TSA); maritime physical and cyber security (USCG); citizenship and immigration services (USCIS); protection of senior officials and safeguarding the U.S. financial system (USSS); and counter-narcotics production and trafficking (HSI). Upon Deputy Secretary Tien’s retirement from DHS in July 2023, he was awarded two of DHS’ highest civilian awards: the DHS Distinguished Service Medal; and the United States Coast Guard Distinguished Public Service Medal. Mr. Tien previously served in the: Obama Administration as a National Security Council (NSC) Senior Director for Afghanistan and Pakistan; Bush Administration as a NSC Director for Iraq; and Clinton Administration as a White House Fellow for the United States Trade Representative.
From 2011 to 2021, Mr. Tien was a Managing Director at Citigroup where he served in numerous senior COO type roles to include being the head of business and process re-engineering transformation for the entire U.S. Consumer Bank. Prior roles include being the Citi Retail Services COO and Chief Technology Officer for the Macy’s credit card portfolio where he oversaw all counter-fraud, credit, payments, and customer service operations in support of more than 20 million customers. At Citi, he was also the Chief Administrative Officer for Citi’s Global Consumer Operations and Technology organization where he oversaw regulatory training for more than 80,000 employees.
During his decade in the private sector and as a retired U.S. Army Colonel, Mr. Tien was also a national leader in the U.S. military veterans community, to include serving: as the national co-chair of Citigroup’s military veterans initiative; as the Board Chair for five years at The Mission Continues (TMC); and on the Bob Woodruff Foundation leadership council. He currently serves: on the Mission Support Council for TMC; on the board of the Avalon Action Alliance which is a non-profit organization focused on nationally scaling proven healthcare programs to help heal veterans and first responders who struggle with depression, post-traumatic stress disorder (PTSD), and/or traumatic brain injury; and as an Executive Partner and Ambassador for Emory University Goizueta Business School’s Masters in Business for Veterans program. During his 24-year active-duty Army career, he deployed for three combat tours to include being the Task Force 2-37 Armor battalion commander in Iraq where he led more than 1,100 troops.
He holds a Bachelor of Science in civil engineering from West Point where he was the first-ever Asian American to hold the position of First Captain as the top-ranked military cadet. He holds an Oxford Master of Arts in Philosophy, Politics, and Economics from Oxford University in the United Kingdom where he was a Rhodes Scholar. He also served as a National Security Fellow at the Harvard Kennedy School. He is a life member of the Council on Foreign Relations.Last Updated: