A Display of Political Relationship

It seems that this "Cart Pool' board at Narrita Airport, Japan is a diplay of Political Relationship . Hierachical order of countries that are (important/friendly) to Japan are USA or any English-speaking country (in English), Korea (Korean), and China(Chinese)! What is also interesting to me is the translation and its of a simply warning 'Use at your own Risk". Korean is the longest, followed by Japanese and Chinese. I don't understand Korean and Japanese, but the tone of the Chinese version is much more polite and humble than 'Use at your own Risk'.