I always wondered why all main European countries are spelled in chinese with a Hanzi that identifies them or some about their origins more the 国 morpheme,
Italy has a uncontested importance in European history, nevertheless its name has been just transliterated to 意大利, which IMHO reveals less participation in its codification.
Is it a matter of when the name was transposed to Chinese language? Maybe it's just the minor influence of the country in that period? I tried to search some information but I couldn't find anything (furthermore, my chinese level reading is extremely low).
The information and the page suggested by @user2619 unfolded my research on the topic:
Seems like all the country names were just transliterated at first. The former name of the well know *什么*国 countries was, e.g.,:
美利坚 --> 美国 法兰西 --> 法国 日耳曼 --> 德国 不列颠 --> 英国 [...]
Later, above for all countries with more strict relations with China, these names were translated to a form more similar to 中国 possibly as a form of bigger respect.
I was teached at a chinese course that the particular 汉字 characherizing the country was somewhat chosen because of some historical reason. For example 法 for the country which invented the constitution. But chinese people I asked say this is not true and has to do with nothing but phonetic reasons. Then as seen in  in some case like 希腊， the sound is taken from the endonym rather than exonym.