In most of Europe, police carry guns. But they are afraid to fire those guns, because there will be a disciplinary process and they are likely to lose their job or go to jail if they can't show there was no other alternative. But if there is a situation where it is necessary to fire the gun, it will be.
Also in Europe more cops have K-9s and aren’t afraid to sick them on suspects.
In the US, anyone can own a gun. Police have to perform a different risk calculus than in Europe.
Police officers are 30x more likely to be murdered in the US South than in, say, Germany.