No, it doesn't have to start with anything. Gun restrictions are just one means to help achieve the goals.
A culture is defined by its laws but also its institutions, media, customs, language. The entire discussion needs to be about the way the US celebrates its military history (independance day, rememberance day), about its rhetoric (like how Sarah Palin talked about "taking out" Democrat senators along with a map with gunsights on their district), its militant foreign policy, its glorification of violence in movies and games, its incarceration rate, "War on..." everything, and of course it's gun laws.
I'm not a specialist in any of these areas but I know how they all interact to create a culture of violence. There's no denying that the US is severley overrepresented in all sorts of crime stats for developed nations around the world. If that's OK with you then fine, but to me that's a problem that needs to be solved. Especially before it spreads to us by ignorant gun lovers on this side of the border.