US sanctions vs UK-Chinese banks

"A senior British banking source said today there was a great deal of annoyance in the City with the US approach. The two British banks most frequently mentioned in Washington in relation to Iran are HSBC and Standard Chartered."

More at:

http://business.guardian.co.uk/story/0,,2130494,00.html?gusrc=rss&feed=networkfron

But surely, it is the fact that these two banks are both Chinese, that makes them awkward to deal with.  It is China that is so behind all the mess in Iran.  They need the oil.  But then who uses the oil?  It is mostly the international companies,most notably giants like Wal-Mart, that use the cheap oil and labour. So it's the US themselves really, isn't it.