That seems like a rather limited view of the word "defense", more appropriate to football or hockey than warfare. Even for that you could have these drones patrolling the territory/shooting intruders.
But the word "defense" is much wider than that. Is the US supplying offensive weapons to Ukraine contributing to the national defense? Even if you feel the US should not be doing that, I hoe you can see the logic of people who do frame it that way.
And Ukraine's in a defensive war against an invader, and for that they have to go on the offense.
(Of course the US renaming the Department of War to Department of Defense in 1947 was 100% propaganda, or to be more charitable, aspirational. There is no question that it has been used offensively).
> Is the US supplying offensive weapons to Ukraine contributing to the national defense?
It's not. It's contributing to European security, and as such is necessary for the US to reaffirm their suzerainty over Europe, but it's not really about US defense and even less about National Security. (I'm glad they do btw, because we European powers would have left Ukraine fall after deciding it would be too expensive to help them…)
> European security is national security via geopolitics.
If you consider “national security” to be a meaningless buzzword and not an actual concept, you can say that. It's as accurate as saying “US sports results at the Olympics is a national security issue via soft power”.
Pretty much everything is “national security” by that standards.
> Being a global superpower has many benefits for US citizens.
Sure, but most of them don't have anything to do with national security.
But the word "defense" is much wider than that. Is the US supplying offensive weapons to Ukraine contributing to the national defense? Even if you feel the US should not be doing that, I hoe you can see the logic of people who do frame it that way.
And Ukraine's in a defensive war against an invader, and for that they have to go on the offense.
(Of course the US renaming the Department of War to Department of Defense in 1947 was 100% propaganda, or to be more charitable, aspirational. There is no question that it has been used offensively).