Business Insider got exclusive access to see how the US Army's Germany-based 2nd Cavalry Regiment is training for a possible war with Russia. A group of soldiers known as OPFOR pretends to be the enemy, practicing the same style of trench warfare that has become commonplace in the Russia-Ukraine war. An Army platoon must traverse mountainous terrain before finding the OPFOR's trench and attacking it. 00:00 - Intro 01:17 - Defending NATO's eastern flank 01:54 - Studying Russia's trench tactics