The crime that chooses these acts call themselves Islamists.
Yes, they do. The Westburo Baptist church also calls themselves Baptist and Christians. They believe they are good Christians. That doesn't make them an example of all baptists or Christians.
Isalmists/radicals and extremists who commit these horrible acts of terrorism do absolutely use their interpretation of the Koran to fuel what they do. They do call themselves Muslims too. That doesn't make them like all Muslims everywhere. It doesn't even make them actually Muslim.
A whole group of people can call themselves a car. They can claim they are THE example of what it is to be a true automobile. (Just like ISIS thinks they are the true believers of Islam.) In the car example, people can even go stand in all their garages and even make honking sounds. We should not ignore the fact that they call themselves cars, because clearly there is something happening that is very wrong.
But no matter how many times they call themselves cars, that doesn't actually make them automobiles.
And before someone says it, yes of course ISIS is a severe existential threat to the existence of western society. I do not mean to imply they are harmless like people pretending to be cars. My point is only that someone can call themselves whatever they want, that doesn't make them actually that thing.
Is this a valid reason to keep immigration from Muslim countries flowing into the West, when it is clear that a ban would save lives and have virtually zero negative impact on our nations?
You keep asking this question or various forms of it over and over. The problem with the question is that it is what is called in debate terms to be a "loaded question" containing a "logical fallacy." Actually several of them.
In order to answer your question, someone has to agree that 1.) it's possible to ban all Muslims 2.) banning all Muslims would prevent anyone new from becoming a Muslim 3.) banning all Muslims would keep terrorists from entering the country 3.) this ban would save lives 4.) there would be no negative impact on our nations.
It's like asking, "when did you stop beating your wife?" To answer it, someone has to agree they beat their wife.
Try asking questions that have less assumptions embedded in them, and you might get more responses or answers to your questions.
It would also be more convincing if you gave evidence of any of the above premises that are embedded in your question, and the conversation might get further than you continually demanding the same answer to the same unanswerable loaded questions.
I'm open to understanding your viewpoint better and being persuaded. But, you simply keep claiming that we will be safe if all Muslims are banned. You have failed to provide evidence or arguments to support your assumption it's possible to ban Muslims or any of the other assumptions made in your position. You have also failed to provide evidence or arguments to support your claim it's possible to eliminate any ideology through banning it, banning Muslim immigrants would end Islam, banning Muslims would end radicalization, or that such a ban would eliminate terrorists from entering the country, or that such a ban would mean we are safe, and that such a ban would have no negative impact... etc, etc.
You have provided no evidence or argument whatsoever other than your simply claiming these things over and over.
Respectfully, just because anyone says something over and over doesn't make it true.