In the 1960s, the left branded US imperialism the major enemy of social justice in the world. Such talk faded after the war against Vietnam and almost disappeared after communism fell in Eastern Europe. It's not that the American brand of informal empire disappeared. It continued through US influences on other states' policies, the sway of US corporations abroad on host governments, US military power, and the power of the Washington-based financial institutions. But, the discourse changed and raged around the softer term globalization. In the past few years, imperialism talk has roared back, led this time by the political right, who gave it a positive sheen. Some on the left have joined in too, in an exciting new literature, revising Marxist and Leninist critiques of imperialism. But, much of the political left and centre are still mired in aspirations for cosmopolitanism, which inadvertently obscure struggles for popular and national sovereignty. This paper examines the limits of cosmopolitanism for democracy, critiques the nature of US power, and discusses how a reasserted US empire has sparked the revival of nationalisms by looking at the cases of nationalism in the six top oil-exporting countries to the US. The paper concludes with inquiries into people-to-people inter-nationalism and whether citizen-based democracy is possible without sovereignty.