If you think America can sustain its foreign policy interventionism, or threat of such, without a fairly martial culture at home, by all means make your case. But I am skeptical. I think it is far more likely that if you brought about gun control, and the cultural preconditions for successful gun control, America’s world role would fundamentally change and America’s would no longer play a global policeman role, for better or worse.Dan Drezner has some interesting methodological quibbles, namely that compositional changes in gun ownership refute Cowen's claim that the US in fact has a 'martial culture' at all. I would add to the critique with a few institutional points.
There are very good reasons to believe that US foreign interventionism would continue regardless of public attitudes over guns or a decline in some broader 'martial culture'. First, the US' ability to intervene globally is conditional on our huge military, which is enabled by our huge economy. Our economic dominance probably isn't going away anytime soon, which implies a continued military capacity that makes it politically easy to intervene.
Second, people with personal military experience are becoming less and less represented among the top ranks of the social hierarchy, due to generational effects and the labor market/career demands of the knowledge economy. This reduction of skin in the game among our elites is a powerful force making it easier for military interventions to happen.
Third, technological changes continue to rapidly reduce the human and political cost of foreign intervention. The rise of drones, cyberweapons, stealth planes and increasingly precise long-range weaponry make modern conflict a qualitatively different enterprise compared to past wars. A martial culture may not be necessary to sustain public support for attacks if attacks become utterly mundane.