The 1st Cavalry Division Forward (1CD FWD) along with Polish ally, subordinate brigades, adjacent supporting commands, and the 7th Army Training Command successfully executed large scale combat operations training in the Defender Europe 2020 Plus (DE20P) exercise in a biologically compromised environment. The coronavirus 2019 (COVID-19) presented many unique challenges and opportunities across all warfighting functions. Still, it proved that it is possible to train in a large-scale multinational exercise while effectively mitigating the contraction and contamination of COVID-19. Through behavioral policies, screening, and testing, the 1CD FWD was able to conduct a high-quality multinational training event, while preserving force health protection and preventing the spread of COVID-19 within the host nation. The 1CD FWD executed a qualitative focus group study and learned that fighting in a pandemic is challenging but manageable and sustainable. The overall protective measures associated with the training exercise did have shortfalls; there were populations that had the potential to bring outside vectors in the training area. Units must create their codified policies, communicate, train, and resource their behavioral and movement systems. Leadership and individual involvement with accountability enforced. COVID-19 tests must be comprehensive, continuous, focused, and targeted as described in the 1CD FWD's ready to fight guide and concept. Recommend one point of restriction of movement and coronavirus test upon reception, staging, on-ward movement, and integration (RSOI) into the European theater.