I'm just curious whether you know what their concerns are and why they did not.....
Secondly—you may or may not be able to answer this--if you're having a dispute and, say, China is the loser, if you will, in a resolution from ICSID, Chinese judicial structures are not what we would call sound, to put a fine point on it.
What faith do you have that countries like China would actually be able or willing to participate fully in ICSID? A lot of countries sign on to a whole slew of treaties and become signatories but don't live up to them at all in practice.