Strategic angle of the Vatican's ecumenical move

I liked this Douthat piece very much. Excerpt:

Here Catholicism and Anglicanism share two fronts. In Europe, both are weakened players, caught between a secular majority and an expanding Muslim population. In Africa, increasingly the real heart of the Anglican Communion, both are facing an entrenched Islamic presence across a fault line running from Nigeria to Sudan.

Where the European encounter is concerned, Pope Benedict has opted for public confrontation. In a controversial 2006 address in Regensburg, Germany, he explicitly challenged Islam’s compatibility with the Western way of reason — and sparked, as if in vindication of his point, a wave of Muslim riots around the world.

By contrast, the Church of England’s leadership has opted for conciliation (some would say appeasement), with the Archbishop of Canterbury going so far as to speculate about the inevitability of some kind of sharia law in Britain.

There are an awful lot of Anglicans, in England and Africa alike, who would prefer a leader who takes Benedict’s approach to the Islamic challenge. Now they can have one, if they want him.

This could be the real significance of last week’s invitation. What’s being interpreted, for now, as an intra-Christian skirmish may eventually be remembered as the first step toward a united Anglican-Catholic front — not against liberalism or atheism, but against Christianity’s most enduring and impressive foe.

Earlier he makes the point that this Benedict's move is not "good manners". But what are good manners going to buy you when your head is being sawed off?