In a Gallup poll, Americans have named Iran as their “top enemy.” But I think part of the problem here is the framing of the question. This assumes that the United States has “enemies” in the sense of nation-states out to compete against or injure the United States. And even with a country such as Iran, I think both the imminence and scope of the threat are not so great as to render them “enemies.”
China is only our “enemy” insofar as America and China have occasionally divergent geopolitical goals, but those goals do not necessarily come at the expense of the other country. Yet, China’s international political goals of favorable trade policies and stability in developing countries’ regimes are quite similar to our own. Iran, even in pursuit of a nuclear weapon, can barely get a handle on its own population and its neighbors, let alone the United States.
Put differently, just because a country exists with geopolitical goals different from our own does not make them our “enemy.” And Gallup, by framing the question as such, continues the militaristic assumption that America must have an enemy at any given time.