If they never surrender, how will we ultimately declare victory?
May have to wait awhile. The war between "Christendom" and Islam has been going on for nearly 13 hundred years. The results have been a see-saw with them ahead most of the time. Part of the problem is the histoical ignorance of our elites. They are taught that the Crusades were agression against peaceful and civilized Muslims. Fact is that it was a counter-attack against them Muslims who were threatening the Byzantine Empire, who had just rolled over the eastern part of it. The Crusaders, howver, had the limited objective of taking back the Holy Land and Syria. Disunity among the Christians eventually led to the failure of the Crusades, which was then followed by another Muslim advance, this one into the heart of Europe, all the way to the gates of Vienna by the 1520s. In the 1570s, the Christians defeated the Muslims in the sea battle of Lepanto, which prevented a Turkish invasion of Italy. Somewhat more than a hundred years later, the Turkis again knocked on the gates of Vienna. This time they were badly defeated and their power began to recede. Their control of the Balkans, however, was not broken until the later 19th Century. About the same time the French won control of North Africa and the British control of Egypt. It was the British and French who kept Russia from taking control of Constantiople. The Ottoman Empire was finally broken during WWI, leading to the establishment of Arab states--and a Jewish "homeland"in Palestine. The Arab states remained under the thumb of Britain and France until after WWII. Here is where we came in. For the post-war history of the Middle East has led to a resurgence of Islam.
They have not surrendered in 1300 years of jihad. The point is not victory in that we finish the enemy for all time. That cannot happen withour exterminating the Mohammedans of the world and I don't think Western Civ is up to that. The best we can hope for is the situation after Lepanto or Tours or Vienna- that Islam becomes torpid with defeat, that the Saracens come to understand that Allah does not will Islam to prevail at this moment in history. That will alleviate the threat for a few generations but it will be back.