In accordance with this article, King Salman’s current mission in Beijing is facilitated by the fact that Mr. Trump is signaling that Iran’s return to the international fold based on the nuclear agreement is not a foregone conclusion- That surely is a valid drive and motive. Trump seems to be right about this point. The article also mentioned that Iranian President Hassan Rouhani might not have a very smooth campaign in the coming presidential elections in May because the lifting of international sanctions has been slow in benefitting Iran and Iranians economically- they used the sanctions as an excused for the staggering economy. But now that they've been lifted, not much has escalated or bloomed. Not even speaking of any strikes and arrests in Iran last year--Chinese strategists are likely to see obstacles to doing business with Iran whether it was a short problem or not. the fact remains it is problematic. But then again China and Iran isn't about friendship but rather assets as mentioned.