Except as a lie and a pretext, nothing. How can that be news to you at this late date?
I think the answer is far more mundane than the “balancing act” you are talking about. The simple fact is that Iran does not particularly want this referred to the UNSC, where they run the risk of even limited sanctions. At the same time they want to continue their enrichment program. That’s why the original Russian proposal of doing the enrichment fell through - the Iranians said, sure, we accept this proposal, but we still want to continue with some minor enrichment activity - which made the entire exercise moot.
If Russia and China back sanctions, then it’s likely that Iran will fold on this issue. Right now Iran is counting on those two (and Japan, India and a couple of other countries with investments in the Iranian energy sector) to help keep any consequences from being very severe.