I am re-posting this comment, so that it is easier to read... Ah! Yes, I can see where that is confusing. "For" is one of those words which is used in many different ways. Here it's used in an awkward way, because to write out what it actually means, takes up a good deal of space on the page. So they decided to make the sentence shorter. The best way that I can illustrate how it is used here, would be these sentences: "What is the Russian word for 'Goodbye'?" OR "Red roses are for love." --------------- In those sentences, the word "for" is used to indicate that the "red roses" are equal to the feeling of love; if you give someone red roses, it is the same as saying, "I Love You". "For" also indicates that the word "Goodbye" would be represented as "до свидания", as spoken in Russian. You can substitute one of those words for the other, depending upon which language you are speaking. In the sentence you posted, "for" is used the same way. It represents the words "is equal to". The size of Rhode Island "is equal to" the combined size of the 17 countries named within the article. Rhode Island is the smallest U.S. state, so the intent of the author was to show how much smaller those 17 countries are. Together, they are the same size as Rhode Island, but separately, they would be dwarved by Rhode Island, if you placed them side by side. [ One ] [ for ] [ more than a dozen ] = [ The size of Rhode Island's land ] [ is equal to ] [ the size of the land of more than a dozen countries combined ] = [ 17 countries are needed ] [ to equal the size of ] [ Rhode Island's land] = I hope this helps!

Based upon the summary you provided, it appears to be in reference to this: That to compare to the size of one country (or state), one would have to add / combine the total land mass of more than one dozen (dozen = twelve = 12) countries. The U.S. state of Rhode Island is equal to the size of 17 of those small countries. 17 is more than 12, so it is "more than a (one) dozen".

Is this paragraph immediately under the title? Is there more? It looks as if the writer wants to describe a vastness. A dozen = 12