The Iranian belief --- if it is is genuine --- that it still has some leverage because of European weakness and fear is significant. It indicates that Tehran will persist with a defiant approach in Moscow. If it even chooses to address the nuclear issue as central, it will restate its demand not only for some enrichment of uranium on its soil, but for enrichment to 20% --- the level beyond bounds for the 5+1 Powers. It will refuse any reduction of activity at the Fordoo enrichment activity, let alone the closure demanded by the US and the Europeans. It will offer no concession, ahead of an easing of sanctions, over inspections and safeguards by the IAEA.
The Islamic Republic will offer none of this because it believes that it can win the game of diplomatic "chicken". The Moscow talks will break up with no advance.
Two weeks later, it will be 1 July and the imposition of the European Union's cut-off of Iranian oil. Then we will see if propaganda and mis-perception gives way to cold economic reality.