They all killed millions of people
Several reasons.
Saw this crusade as a blessing from God.
Christians would stop fighting themselves.
Christians that would fight would go to heaven or be right with God.
To take back the holy lands, from the Muslims would be a righteous cause.
Anabaptism is the name for several related branches of continental European lay Protestantism. These groups first began emerging after 1525 and were most prominent in (but not limited to) German and Dutch speaking territories. In German and Dutch the terms Wiedertaufer and wederdooper (rebaptizers) carry old, negative connotations
The United States sent peacekeeping forces to Bosnia-Herzegovina in 1996.
Bosnian Serbs had been carrying out a campaign of ethnic cleansing against Bosniaks and Croatians. The United States also was involved in the Dayton Accords in November 1995, which were aimed at resolving the conflict in the Balkan region.