Sanctions in place to deter from nuclear program

The US and the EU have put in place new restrictions to limit the oil exported by Iran. however for the sanction to actually put Iran off pursuing its nuclear program, it relies a lot on the Asian countries such as China and India. China has already halved its number of imports from Iranian countries. But will the sanction actually been affective? Countries such as Bejing are seeing this as an opportunity to get cheaper deals on oil from Iran instead of cutting them off.
http://www.reuters.com/article/2012/02/13/us-iran-sanctions-asia-idUSTRE81C1C320120213?feedType=RSS&feedName=worldNews