First of all he was well educated. He knew not only how to win battles, but how to use his victories to his advantage. When he saw things of value, he did not hesitate to incorporate them into his culture or his thinking.
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".
<span>A. provided a precedent for international cooperation and justice for all war crimes</span>
