I agree with everything in Naomi's post apart from this:
"... the people we are now obliged to deal with possess a mind-set that bears no resemblance whatsoever to anything that our civilisation has ever encountered before.".
The West may now have forgotten, but for a thousand years it suffered subjugation, enslavement and slaughter at the hands oi Islamic fundamentalists with just that mind-set.. The mind-set is as old as Islam. In the most literal sense (submission, i.e. us to them) it IS Islam. Mohammed: "I have been commanded to fight people until they testify that there is no god but Allah and that Muhammad is the Messenger of Allah". This is what the Prophet taught and what he,and his successors practised.
Within a hundred years of the Prophet's death Islamic jihad had captured Damascus, Cairo, Jerusalem, had subjugated the whole of Christian North Africa and seized most of the Iberian peninsula. The last outpost of Easter Christianity fell in 1453 establishing the Ottoman caliphate.. The attempt by the Ottomans to subjugate the West was repulsed at Lepanto over a hundred years later. The victorious forces were a coalition of Christian forces from southern Europe organised in part, I believe, by the Pope. (No appeasing Francis he!). The Ottomans tried again a hundred years later at Vienna, this time being defeated by a Christian coalition from the north. Even after the scientific revolution following the 17th century Enlightenment gave Europe a technological superiority which remains to this day and has made it invulnerable to military invasion, the Islamic states of the Barbary coast continued to follow the example of the Prophet , disrupting commerce in the Mediterranean by attacking infidel ships and enslaving or holding for ransom their crews. (Christopher Hitchen's biography of Jefferson is an interesting read about that period of history. One of the down-sides of independence was that the merchant ships of the American colonies no longer had the protection of the Royal Navy. He also mentions the visit of a representative of the Bey of Tunis/Algiers(?) to the newly independent states - the event from which Obama fancifully invented the "first iftar in the White House").
More realistic than any president in recent years, John Quincy Adams wrote:
"The precept of the koran is, perpetual war against all who deny, that Mahomet is the prophet of God. The vanquished may purchase their lives, by the payment of tribute; the victorious may be appeased by a false and delusive promise of peace; and the faithful follower of the prophet, may submit to the imperious necessities of defeat: but the command to propagate the Moslem creed by the sword is always obligatory, when it can be made effective. The commands of the prophet may be performed alike, by fraud, or by force.".