NATO ended its largest and most complex computer-assisted, command post exercise of the 21st century on 19 October. Exercise Steadfast Jupiter 2023 included more than 7,000 personnel from 17 NATO nations and 24 multinational headquarters exercising every aspect of military operations from the strategic to the tactical levels.

“The future of warfare has become increasingly complex as highlighted by the crisis that is currently occurring on NATO's eastern flank,” said U.S. Army Lt. Col. Jennifer Gotie, U.S. senior Army officer at the Joint Force Training Centre in Bydgoszcz, Poland, who travelled to Brunssum to serve as an evaluator for the exercise and analyze how to improve multi-domain operations within the NATO force structure. “I have been given the unique opportunity to support the development of NATO multi-domain operations by bringing in over 10 years of U.S. Army MDO concepts.”

The defensive exercise was designed to train and evaluate 24 training audiences located at 27 different locations in Europe and North America.

“Steadfast Jupiter 23 is important for U.S. national security because it allows us to maintain a presence with our NATO allies and assist them with the defense of NATO territory within Europe and deter our adversaries,” said U.S. Army Maj. Thomas Artone, Allied Joint Force Command Brunssum, counter-improvised explosive device staff officer. “For the past week in Steadfast Jupiter 23 my section, the counter-IED section within the J3 has been focused on activities to attack the network, defeat the device, and prepare the force as well as counter other hybrid and UAS (unmanned aircraft system) scenarios.”

The exercise was a “milestone in operationalizing the concept for the Deterrence and Defense of the Euro-Atlantic Area (DDA): a strategy for the short to medium term that enables allies to rapidly strengthen NATO's deterrence and defense posture in all domains,” according to a press release published by NATO’s Allied Command Transformation.

The exercise was based on a simulated Article 5 scenario. Article 5 of the North Atlantic Treaty is NATO’s central precept that an attack against one ally is considered an attack against all allies. The exercise tested NATO’s responsiveness, command and control, and defense posture in a highly challenging multi-threat environment.

“It's been a very good exercise to challenge our systems, really test our systems and processes, not only for how we receive information, how we analyze information and how we distribute information not only to our higher headquarters but also painting the picture to our subordinates,” said U.S. Army Col. Jason Lojka. “This is a great opportunity to help strengthen the alliance and to contribute to our overall security posture in relation to our regional plans and also the road going forward in regard to how the United States approaches security internationally.”

Each of the 24 participating units had specific objectives for Steadfast Jupiter. One of JFC Brunssum’s objectives was to help prepare the unit to take command and control of NATO’s Response Force in 2024.