"If Charles Martel had not checked the Saracen conquest at the Battle of Tours, the interpretation of the Koran would be taught at the schools of Oxford, and her pupils might demonstrate to a circumcised people the sanctity and truth of the revelation of Mahomet. Had Pilsudski failed to arrest the advance of the Soviet Bolshevik Army at the Battle of Warsaw, not only would Christianity have experienced a dangerous reverse, but the very existence of Western civilisation would have been imperilled. The Battle of Warsaw saved Central and most parts of Europe from a more subversive danger – the fanatical tyranny of the Communist Soviet. All of Europe at this time, after World War I, was in ruin, and a strong conqueror could have imposed a tyrannical system from Russia in the East to France, and possible Britain in the west. The army that had marched on Warsaw was over a million strong and was nearing the gates of Warsaw when the Polish Cavalry attacked at the Bolshevik hind-quarter. The Bolsheviks were so surprised by a viable and active military response to their sure victory that the Bolshevik army in shock routed and fled in complete disarray. The Polish western boundary stood until 1939 and World War II. On the essential point, there can be little room for doubt; had the Soviet forces overcome Polish resistance… Bolshevism would have spread throughout Central Europe and might well have penetrated the whole continent."
January 1, 1970
https://en.wikiquote.org/wiki/Polish-Soviet_War