Quick: Would have or Would had

In 1095 Pope Urban II called for the First Crusade in a sermon at the Council of Clemont. An ethical warfare waged on behalf of some ideal believed to be for the benefit of mankind and to be so beneficial that warfare is justified. I always wondered, had the First Crusade been a disaster, the next to follow, may be, wouldn’t had. [followed]

Is it write to use wouldn't had, or wouldn't have been or have would be more fitting. Just need a quick sanity check.