Image © Austin Cline, Licensed to About; Original Poster: Library of Congress
Christianity is supposed to be a religion of peace. Despite that, Christians often find themselves embroiled in violent conflicts where their religion is utilized to motivate them to kill. There are plenty of nasty examples in history and the Crusades stand out as especially strong, but Christians in modern America are not immune from the call to go out and kill despite the injunction from their Lord and Savior to not strike out against those who hit you.
Today's most popular target of rhetoric encouraging violence are the "Islamofascists." Muslim extremists aren't anywhere even remotely close to fascists, but a label incorporating "fascist" helps people believe that they are in a fight for world civilization not unlike the fight against fascism and the Nazis in the mid-20th century. This is important not just because political and religious leaders evidently think that their cause is so weak that they can't advance it without associating the current enemy with a past one. It is also important because of what it says about their goals.
When people fight against an enemy who is presumed to be an existential threat - a threat to one's existence and the future of civilization itself - then it is easier to justify all manner of extremist responses. Niceties like civil liberties and human rights may be appropriate for parlor-room conversations in peace time, but when locked in a violent struggle where defeat means the end of one's existence and the end of a civilization that can even conceive of civil or human rights, then it hardly seems appropriate to tie one's hands and risk losing everything.
This is how the struggle against fascism and Nazism was portrayed, and there was some justification to that. Even so, standards of civil rights and human rights were generally upheld. Today the Christians associating the threat Muslim extremism with the existential threat of fascism are also those who tend to dismiss the idea that traditional standards of civil rights or human rights must be maintained.
Is that What Jesus Would Do?
The above poster was created from an American World War I poster encouraging people to give to the Victory Fund campaign. The original text was "Shall Chaos Triumph" and evidently meant for people to give as much as possible to advance the military campaign against the Huns - who during this era were described in terms not too different from how American Christians today describe the "Islamofascists" among Muslims.