Mishra’s answers also indicate opportunities missed by the Congress by not talking to the BJP more. This has been a Congress problem. On pension reforms, for example, it has waited for minute quasi-concessions from the Left and not forged an issue-based parliamentary deal with the BJP. On the nuclear deal, pro forma approaches were made and documents shared. But there was never ever any indication that the Congress seriously wanted to engage the BJP in the sense of two big national parties deliberating on a major national issue. The Congress can point to many things BJP leaders have said on the deal to argue that such an engagement would have been futile. But that may be — deliberately? — missing the point that in politics, substance is often critically dependent on form.

Not that the BJP’s substance on the deal wasn’t stunningly counter-intuitive. The party has never convinced anyone why it took the position it did and officially still does. Whether there were intra-party rivalries that trumped responsible politics. And what domestic political constituency did the party have in mind when taking an almost absurdly maximalist oppositional position on the deal. It is common to say the nuclear deal is hard to understand. Nuclear deal politics is probably a harder puzzle.