Ross Douthat sees that the Pope understands the world stakes in his opening to the Anglicans: It's about standing up to Islam.
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.