You are completely wrong. Nikki Haley is explaining that Russia crossed a red line. Without red lines Russia can kill anyone anywhere whenever they feel like it. But the nice thing with a red line is that if Russia doesn't cross the line, we can be productive partners in many areas, e.g. eliminating ISIS. It would be lovely to have a magical world where we don't need such red lines. But that's not the world we live in.
Why not. Our guys do it all the time - even in this country, even U.S. citizens.