In June '16, Felix Sater wrote Michael Cohen and said if Cohen accepted an invitation to Moscow for before the GOP convention, he'd meet Putin. Cohen declined—then went to Italy for a "vacation" where his alibi on where he went has fallen apart. The dossier wasn't wrong on Cohen.
2/ The Trump team always discussed meeting Russians in "neutral" cities rather than Moscow or D.C.; they'd already used Italy for that purpose with Papadopoulos in March 2016. So the chances Cohen didn't meet with any Russians in Italy (or Prague) just before the RNC is very low.
3/ My point—most don't know the whole story on Cohen. I've been researching it and it's much worse than people think. Do not believe any news report implying that Cohen is useful to Mueller only on campaign finance violations. Mueller wants Cohen on the Russia collusion question.
