Historically, we have associated terrorist attacks with bombings, but last week’s terrorist attacks in Paris also included terrorists shooting people.
I think we can assume that what happens in Europe will eventually come to the USA. We are fortunate that all fifty states now allow some legal form of concealed carry of a firearm for self defense. However, that firearm is only a useful tool if we are competent firearms users. That means that we get competent training on an ongoing basis; that we practice what we have been taught until we are competent and that we carry our firearm regularly.
When we get into our car, we buckle up our seat belt—not because we intend to have an accident, but because we don’t know when or if we will have one.
Carrying a pistol should follow the same logic. Like car accidents, Terrorism and Crime don’t make appointments, they just show up.