Supposedly, there is a nefarious cabal of malicious nations looking to dump the dollar via oil producing countries. I have a hard time with this for two reasons:
1) China is one of the supposed countries. China has the largest reserve of US dollars outside of the United States. The US is also their biggest trading partner. Their financial position is prefaced on the strength of the dollar. Dumping the dollar would hurt the US the most, but hurt China the second most.
2) China manipulates the Arab countries on a daily basis. I don't believe much when I hear that there is a rumor of an agreement between China and Arab countries. China will string them along and then turn around saying "I have no idea what you're talking about."