According to estimates, US government bonds of around USD 2.1 trillion and overall reserves of USD 6.5 trillion4 are held by emerging market economies. However, standard methods to quantify the optimal level of reserves suggest that the current level of reserves would not be justified purely for precautionary motives.
It would be advisable, therefore, to utilise some of these excess reserves to stabilise the international monetary system, while Europe is enhancing its firewall. One obvious way to do this would be via the IMF. The IMF could borrow global excess reserves and use them to support programme countries that are  4  Data on US government bonds is from TICS: http://www.treasury.gov/resource-center/data-chartcenter/tic/Documents/mfh.txt.