Jonathan Schell has a lengthy piece in the Nation arguing that the U.S. can’t be an empire even if it wants to. He attributes this to the fact that recent history has imposed limits on the use of force which prevent any country from being the new Rome or British Empire. The two most important constraints are nuclear weapons, which make great power wars like the World Wars all but unthinkable, and the anti-colonialist mentality which encourages people who might be absorbed into a world empire to fight for self-determination.

However, Schell says, many policymakers, presidents, and pundits are reluctant to concede any inherent limitations on our power. They prefer to see lack of will displayed in a reluctance to use that power as the only things holding us back (compare Matthew Yglesias’ “Green Lantern theory of politics”). Schell traces a line of thought going back at least to Joseph McCarthy which blames American failure and decline on subversive elements within who are sapping our will to prevail. The danger, he argues, is that this can result in a backlash against liberty at home as authorities seek to restrain those subversive elements.