With the end of major combat operations in Afghanistan, how will the North Atlantic alliance maintain the unprecedented levels of interoperability developed over the last decade? One of the most effective means of building and maintaining interoperability—the forward-based presence of US military forces in Europe—has shrunk significantly over the last 25 years and is likely to shrink further in the coming years, meaning it will become increasingly difficult for American and European military forces to operate side by side. Nevertheless, the United States continues to look to its allies in NATO as the primary partners in maintaining and promoting common interests around the globe. Additionally, Washington seems more committed than ever to wielding force in a coalition context. In order to help remedy this seeming incongruity, Washington announced in early 2012 a plan to deploy rotationally several hundred troops from the United States to Germany for periodic exercises with European partners and allies. However, it remains unclear whether a rotational model will be sufficient to generate the level of interoperability necessary for US forces and those of its most capable European allies to work seamlessly across the range of military operations. The loss of tactical and operational interoperability threatens transatlantic strategic interoperability,and therefore risks decoupling European and American security policy. To mitigate these challenges, the article discusses several policy steps the United States should consider.