The United States is well placed to remain the leading power in the twenty-first century, but it will have to learn to work with other countries to share the leadership role. Washington should adopt a strategy of providing global public goods analogous to the role the United Kingdom played in the nineteenth century, and it will need to combine its 'soft-power' and 'hard-power' resources into a 'smart-power' strategy. The paradox of American power in this century is that the largest power since the Roman Empire cannot achieve its objectives by acting alone.