Parent's comment had nothing to do with military, but with an authoritarian executive's power to unilaterally get things done quickly, if they so desire.
The US was sometimes able to mobilize quickly in response to extraordinary circumstances (WWII production being an example), but that isn't really our default state, and requires consensus-building rather than orders from on high. But sadly our ability to do so even in extraordinary circumstances has atrophied.
It's perhaps worth noting that even in the U.S., these wartime mobilizations have often been carried out by comparatively authoritarian governments (especially in comparison to peacetime U.S. government), e.g. the suspension of habeas corpus and mass arrests during the U.S. Civil War, German internment and the Espionage and Sedition Acts of World War 1, and mass Japanese internment camps and the Office of Censorship during World War 2.
An entirely accidental comparison - I recently finished a series of novels set in the US's pacific fleet during ww2, so that was simply the example at the forefront of my mind.
But as a European, the US's military footing doesn't feel alien to us at all. They're essentially the modernization of the British Empire, in that their single greatest "weapon" is force projection, rather than the million-man-armies of the East. We don't necessarily identify with it anymore, but it still feels more familiar than alien.
As a percentage of GDP, the American military isn’t massive. It’s smaller than China’s. It’s smaller than India’s and only slightly bigger than little North Korea.
The US was sometimes able to mobilize quickly in response to extraordinary circumstances (WWII production being an example), but that isn't really our default state, and requires consensus-building rather than orders from on high. But sadly our ability to do so even in extraordinary circumstances has atrophied.