Pat. I must respectfully disagree with your analysis.
When we suggest that a nation (spell tribe) can and will recognize a mortal threat -- and take actions required for its survival -- certain assumptions are implicit in the thesis:
1. That the nature and identity of the "threat" is definitive; with clear options available in addressal thereof. Incremental demographic shifts -- with attendant social and cultural modifications to the tribal makeup -- make such options ever more difficult. (Who and where is the "enemy", etc...)
2. Building a consensus for unified action against the threat becomes ever more difficult -- if not impossible.
It seems to me that the biggest enemies Western Civilization has in this conflict with Islam are, in fact, TIME and an attendant diminution of NATIONAL WILL.
Happy New Year to all.
In the UK, the 'enemy' is the Pakistani, in France it is the NA Arab, in Germany, the Turk, and so on.....
When the time is ripe, there will be politicians who will use it as an opportunity, and help develop a consensus.