Exercise Koolendong 2021 is a planning and field training exercise between Marine Rotational Force – Darwin (MRF-D) and the Australian Defence Force (ADF). The exercise enhances the ability to conduct combined operations, enhances interoperability, makes a more capable and postured force, and demonstrates the strength of the U.S.-Australian alliance. The purpose of the exercise is to strengthen the U.S.-Australian relationship, enhance and validate Marine Corps-ADF interoperability across the warfighting functions, and enhance MRF-D’s capability and structure as a crisis response force in accordance with Commandants Planning Guidance concepts.