The fastest way to end Islam is to outlaw and incarcerate liberals. Without liberals funding them, defending them, excusing them, enabling them, importing them and surrendering to them, Muslims would be quietly screwing goats in the middle east and killing each other to the planets ultimate benefit.
up to a point, you will have to deal with the muslims themself in the end, The Umayyad invasion of Gaul where muslims attacked and ravaged europe until they got stopped at battle of tours was not caused by liberals(due to them being pretty much non existent in the 7 century) or the siege of vienna , we are now in the third islamic crusade against the west that started at 911