the united states congress has passed a resolution to put sanctions on refined petrolium products to iran. as far as i know, thus far there has been no call to boycott sale of crude oil from iran. the obama administration's approach to sanctions might be different but probably less effective. however, an agreement on sanctions regime, even one which is not fully effective, is desirable. sending iran a message by the world superpowers would be important in order to exhaust all diplomatic avenues. your claim that qom is empty is not believable given the public denounciation by obama, sarkozy and brown of iran regarding qom.
from the article: Israel shows China evidence of Iran bomb program