How come Jesus used to greet people saying Peace be unto you, just like Muslims do, but most Christians DO NOT?

I'm going to skip all the religious things and go to the soldiers you are referring to...American soldiers were and are poorly prepared for all the cultural nuances involved in being in countries in the Middle East..it's sad I know but it's true...they are not intentionally being disrespectful..it's a little ignorance..as in they do not know these things about your culture...Just as you would not know things about my culture if you were to come here..in South Louisiana we have a very rich culture..though it's kinda hard to offend us..I'm sure there are things about us that you would never think to be offensive that would be to us...for instance here it's considered rude to wear head coverings at a table to eat or in someones home...your culture is clearly different on that. Maybe instead of focusing on all the differences between our cultures and beliefs you may find some common ground then from there begin to educate us on what is different...Peace be with you...Christians do say this.