I think that this quote is about ultranationalism, but my friends think that it is about internationalism. Which one is it?
To me, this quote makes me think about viewing humanity as a whole and not paying any attention to country lines. We have a higher duty to our fellow human beings, regardless of the country. This can be interpreted as internationalism, but to me that sounds more like cooperation with different countries. This quote is about humans as a whole, and how we need to look out for fellow humans regardless of country.
I have to agree with your friends as well, the quote is internationalist in sentiment. The only qualifier I would give is that the quote was from Oscar Straus, one of Theodore Roosevelt's cabinet, and certainly Roosevelt would have subscribed to the views described in Post 4, believing that white Anglo-Saxons had a duty to spread and protect civilization. But Straus also worked in support of a League of Nations after World War I, and while I have been unable to ascertain the date of this quote, this sounds like it must have come from that effort. To make a larger point, I would like to emphasize as a history person that you often need to think about context when you try to characterize what a quote means.
Here is a link to a bit of information about Straus:
The only way to see this as ultranationalism is if you are going to say that "the trust of civilization" is something that only your kind of people could handle or protect. This would be like Hitler saying that he needed to be true to the ethnically Aryan people rather than to the state of Germany. But overall, I agree with the others that this is a statement of internationalism.
This looks like internationalism to me. Internationalism looks beyond state boundaries for cooperation and the benefit of more than just one country. This statement speaks of a patriotism that does not focus on just one country. It calls for a duty to "mankind," rather than "country."
I am sorry to say this, but I would agree with your friends. The phrase "not limited by the boundaries of one's country" seems to take any form of nationalism out of the equation in my eyes. Safeguarding civilization above your own nation would fall under internationalism in my opinion.