NATO used to be the world's most formidable military alliance. But its original reason for existence, the Soviet Union, disintegrated years ago, and its dreams of being a world cop are withering in the mountains of Afghanistan. Meanwhile, the European Union's (EU) Common Security & Defense Policy (CSDP) has deployed 27 successful military/civil missions from Africa to Asia in the last 10 years. Through CSDP, Europeans are increasingly taking charge of managing their own foreign and security policy. NATO is no longer the sole and preeminent Euro-Atlantic security actor. But watching NATO fade into irrelevance would be a mistake. It is a tried and true platform to harness the resources of North America and Europe. NATO's future usefulness depends on its willingness to accept its reduced role, to let the EU handle the day-to-day security needs of Europe, and to craft a relationship with CSDP that will allow North America and Europe to act militarily together, should that ever become necessary.