America imperialised the whole Middle East ages ago. American companies have had control of the majority of oil reserves there for a long time. Imperialism isn't just about armies and invasions.
You could also argue that America uses cultural imperialism across the globe. Many countries' traditional beliefs and practices are being eroded by the American system. This is all in the name of increased profits for American companies of course.
That being said, I don't think it's unethical. It's just the way capitalism works.
Imperialism is three parts
Economic, Political, Military
All three
It's unethical
It's racist
