A quiet revolution is underway in Europe: import substitution in the defense sector. The EU intends to free itself from American technology so it can develop and sell weapons without having to seek Washington’s approval. The shift has been driven by growing disagreements with the U.S. over a range of issues — aid to Ukraine, trade tariffs, and repeated American threats to withdraw from NATO. As a result, Europe has concluded that it must invest in its own security and strategic autonomy. But money alone will not be enough. The continent also needs to bring order to its fragmented defense industry, and that will not be easy given the wide range of weapons systems in use by its various national armies and the risk that populist politicians pose to long-term planning. Meanwhile, Poland and the Baltic states have demonstrated little faith in Europe’s defense-industrial independence and continue to buy American weapons. However, Brussels’ new rules will require them to give preference to European manufacturers.