We, the free, face a daunting opportunity. Previous generations could only dream of a free world. Now we can begin to make it. In his welcome alternative to the rampant pessimism about Euro-American relations, award-winning historian Timothy Garton Ash shares an inspiring vision for how the United States and Europe can collaborate to promote a free world.

At the start of the twenty-first century, the West has plunged into crisis. Europe tries to define itself in opposition to America, and America increasingly regards Europe as troublesome and irrelevant. What is to become of what we...