Alan Rusbridger's ordeal by home affairs select committee was a something of a triumph for the embattled Guardian editor. He seemed totally on top of the facts, challenges and responsibilities of the Snowden case, leaving the attack dogs of Westminster yapping vacuously. But hey! That's probably what you'd expect me to conclude – just as you'd expect, and get, a totally different Daily Mail verdict oozing bile – so put all that to one side for a moment and consider a few second-phase issues rapidly assuming primary importance.

One, for David Cameron, will be what happens when yet another long-running Scotland Yard investigation, this time embroiling dozens more officers charged with deciding whether the Guardian broke section 58A of the Terrorism Act, reaches fruition. Is there a technical case for prosecution and trial? That's not Downing Street's call, just as trying Clive Ponting over leaks about the Belgrano wasn't No 10's call almost three decades ago.

But remember that Ponting was acquitted, quite openly, because a jury thought he'd done the right thing (whatever government lawyers and foaming politicians said). Then think of the Guardian and the New York Times in the dock with Jon Snow trying to scramble aboard – and Barack Obama plus Angela Merkel joining a chorus of incredulity over British imbecility.

Those who actually watched Rusbridger defending his decisions in detail last Tuesday may have recalled the admirable Ponting. Those Tory MPs who were barely out of junior school at the Belgrano moment should look back and ponder. Who wants to appear drop-dead stupid when the court you longed for finally meets? Loving your country means knowing its history, too.

Phase Two also brings us back to Leveson, royal charters and rival press regulatory bodies. Rusbridger won't be taking the royal charter medicine (as he more or less told the select committee). Who wants a swarm of MPs pothering about patriotism and pulling your charter strings? The Guardian won't opt for that kind of punishment. But will it join the independent alternative as 90% of national publishers sign on the dotted line – and thus sit side by side with Mail high-ups who still hate the pieties of hacking? That's more problematic while the seething goes on. The FT, Indy and (most crucially) the Guardian still sit outside and ponder.

A wise Mail would can the vitriol and concentrate on persuading the Guardian to join Ipso too. Nothing, in purely practical terms now, could validate the new body better, or testify to its real independence. But is the Mail wise in perceiving the paths of necessary peace? Denunciation, denigration, destruction, yes: but consensus, persuasion… ?