If you actually believe that, you should never get involved if you see someone breaking into your neighbors house. After all, you probably have enough trouble under your our roof (like most uf us have), to get involved in calling the police or trying to stop the burglers. And, they will not be bothering you if they are breaking into your neighbors house. If you see someone in a hit and run, don't get involved! You need to worry about getting that pack of smokes from the store you were going to when you saw the crime.
If you see a teenager driving like an idiot through town, don't get involved. It won't be you that gets run over by his reckless driving.
Why should we have gotten involved when S H (saddam Hussein or Sh$# Head, your choice) invaded Kuwait? Those people are not us.
There is no difference in these scenarios, just the scale has been changed.
I have seen many of the places we have "gotten involved in" and many we have not. The world is a better place because of the United States of America!