How would the U.S. be different today if there had not been imperialism?

How would the U.S. be different today if there had not been imperialism?
Someone told me that there would be fewer wars, but they didn’t explain why. And what else would be different?

I have to write an essay on this topic (for an online course), but I am struggling a bit-the text I was given was hard to understand . In the assignment, I was also warned not to confuse imperialism with colonialism… but this only confused me more.

Were it not for imperialism, the United States of America in its present form would not exist. The New World would have never been subject to the imperial aspirations of the English, French, Spanish, Portuguese or Dutch. Of course, without imperialism, the Romans would have never extended its power into present day England, France, Spain or Portugal amoung others. Nor would they have extended their power into the Palestine and Christianity would have never had the ability to flourish throughout the empire. In short, the history of the world would have been very very different.

Of course, if you mean how would the U.S. be different today if it not had been for (only) HER imperialism, you could atleast lop off all of the territory she picked up in the Mexican-American War. Take away Hawaii too. Even the territory she did have, without imperialism (which is unequal relationships between states and their, at times, absorbtion), she would have never been able to utilize her lands as they would have been populated by native American tribes. She would be a poorer, less powerful country who might have become the subject of the imperialism of other nations.

But maybe you mean only the imperialism after, say 1898, assuming that the US engaged in no imperialism and the rest of the world continued to do so. The answer would be, no there would not be fewer wars. The US would have been involved in fewer wars, as her interests would not have collided with others as much, but there would just be a different superpower (Japan, for instance) getting into all of them.

Imperialism is a loaded word really. It has bad connotations, but all powers have done it and it is an undeniable force in human history (and can be argued in the animal kingdom too).