I think that the best answer is the geographic location: many other countries (Sweden for example) have tried being neutral at different times but did not manage to: but the fact that the US has only two boundaries, and that both other countries also have a history of fighting from independence from a European power, makes it possible that unless US decideds to get involved in international politics, it can be "left alone".
Answer:
steel.
Explanation
got all the answers right on edg Hope this helps!
Your answer would be D. hope that you pass!
