Evangelicals are past masters at snatching defeat out of the jaws of victory, but one can just imagine the arguments going on. Just as in any politburo, the ones who are at the centre argue like fury when the chips are down. What may well keep them in Jerusalem, lock, stock and barrel, is the fact that it all connects with the right wing Christian-Zionist group and its money. To back away might look like a defeat in the face of Palestinian concerns, and this would not do.
The agenda of Christian Zionism (and for a British shoestring budget satellite version just look at Revelation TV) is to set up a situation of Jews returning to Jerusalem so that Christ will return in glory - the second coming. It is a hard line evangelicalism at work.
It could be that there is a dividing point here with extreme Anglo-Catholics, who still may have a respect for Bishop Suheil and his patch. At this point GAFCON will want to carry the Anglo-Catholics (who can be dumped later). No one will give a stuff for the Anglican Communion, but in building up your own vanguard you don't want it to be wrecked before it gets going.
Tom Wright is acting as the big man again, chucking his weight about in an article called Evangelicals are not about to jump ship, and acting as "friend of the Archbishop" - like his tough guy bodyguard. He is pitching in against GAFCON - and he is happy to quote the Advent Letter, otherwise only quietly acknowledged by the embarrassed.
The rationale of GAFCON (the Global Anglican Future Conference) is: "The Communion is finished; nothing new can happen; it's time to split." No mention is made of the Windsor report, the proposed Anglican Covenant, or, indeed, the Archbishop of Canterbury's Advent letter, insisting as it does on scriptural authority, which GAFCON seems to regard as its monopoly.
That last point is crucial. To say "scripture is our authority" does not commit anyone to joining the small group represented by Chris Sugden, Martyn Minns, and Peter Jensen...
We know that his sort of evangelical is divided from the GAFCON sort of evangelical, but there could well be some infighting down in GAFCON land, as one would expect among the true vanguard.