Suppose we frame the question this way, "The US Empire puts major bases all through Europe, the Middle East, and Asia, but not no major bases in South America or Africa. Why is that?" (We're doing some rounding here because, yes, for example, the US has a big drone base in Africa but it sure ain't Incirlik.)

People could point to any number of reasons, but I would land on two. While they're interrelated, they're also quite distinct.

The first is that they're not contemplating a war where big bases in SA or Africa would be important. Big bases in Japan and arming up Taiwan with an eye towards China? Sure. Bases in Romania and turning all of Poland into an armed camp against Russia? You bet! Guns and planes and bombs all over the Middle East against everywhere else in the Middle East, particularly Iran? You know it!

There really aren't anything like the same sort of prospective campaigns in SA or Africa. There aren't really any significant opposing militaries. Venezuela and Cuba come to mind, but they're just across from Pensacola and Tampa. No problemo.

Which brings us to the second reason: the whole mindset is different. You can see from the original article that the entire underlying mindset is colonialism. Like, "Hey, ain't those Chinamen ever heard of the Monroe Doctrine? GTFO!"

Which brings us to what underlies the second reason: racial superiority. See how everything eventually is geared around, "All those greaseballs and darkies belong to us. We'll take their shit when we're good and goddamn ready. Oops, I mean, we'll take our shit." So the entire military approach involves taking our shit from these mud people who seem to have some objection to that.

(Sorry for the rough language, just trying to make a point. I'm certainly not in a warship off someone's coast with an eye towards taking anyone's stuff.)

Final note: it's not really even racial superiority, although "They" leverage any that is already existing. The people running the game will murder, rob and oppress white people just as enthusiastically as brown people (see Ukraine), but historically the more melanistic people ended up lower down on the totem pole, and therefore softer and higher priority targets.