It seems to me they may have a point. How did Israel escape sanctions?

"Iran currently enriches uranium up to 20 percent — far short of the 95 percent level needed for an atomic weapon — and justifies its decision to go to higher enrichment levels by saying it needs to make fuel for a research reactor producing medical isotopes."

http://www.commondreams.org/headline/2010/06/18-0

The quote above is wrong. 20% enrichment is good enough for a low yield bomb. The medical isotopes rationale is plausible.