No less than India or Japan.. Taiwan is not border disagreement but just separatist issue. Mongolia border no issue but just these group of loser are jealous of rise of China and the evergrowing strength of us. India , as always try land grab in China , Pakistan and Nepal. Japan, left with Diaoyutai only. Vietnam, another fool manipulate by US to start over claiming the territories.So, just out of curiosity, how many border disagreements do you guys have? (not counting the EEZ) India, Vietnam, Taiwan, Mongolia...?
Remeber, not a single central asia countries has border issue with China.