I researched a bit into it several years ago, however, I never documented sources. But You have to look up Fr. Edmund A. Walsh S.J, an american Jesuit who actually brokered the deal. The masonic powers had already infiltrated much of the US episcopacy. Unfortunately it was to those clergymen whom Pope Pius XI had lent his ear.
Jésus Degollado, commander in chief of the Cristeros, addressed his troops, his voice breaking from sorrow:
Six thousand Cristeros obeyed, and were immediately massacred. In three years, they had only lost 5,000 men in combat! The Mexican episcopate decreed the excommunication of the Cristero priests, but those who had not been killed during the war (180) had already been martyred...All was lost.
More Cristeros were killed after the "arreglos" (Truce) than during the official 3 year war.
Is it not suspicious that this is the time period when Bella Dodd and those who were with her were allowed to recruit a great many enemies of the Church into the priesthood