When I run into people that claim the Crusades are responsible for the conflict between east and west I like asking “if that is true why did Charles Martel stop the Islamic advance into France and Spain 100 years before the Crusades started?”. Usually I get a blank look and silence.
Given the the First Crusade was from 1095 to 1099 and the Battle of Tours was 732, you need to say 'more than 350 years' before the First Crusade! Not arguing with you, just saying the time frame is even more emphatic! You can also toss in Islamic slave raids on the Mediterranean and South Atlantic European coasts all of the way into the 1400s and raids against Rome from conquered Sicily in the mid 800s. North Africa-based Islamic Pirates menaced commerce in the English Channel well into the 1600s under the support of the Ottoman Empire.