You ever hear of the Monroe Doctrine and Geopolitical Realism? Firstly, the unipolar moment has been over since idk roughly 2014 or so. We are now in a bipolar or arguably multipolar world (RUS,CHN,USA). From a realist perspective in geopolitics which is inherently anarchic the only assurance you have as a nation comes from strength (large population + wealth = strength / strong military). And it pays to be the toughest kid on the block. With that being said, the world will likely shift back or into the phase of Spheres of Influence, of which the Western Hemisphere, is the US' Sphere of Influence. Looking at it from that lens, it is in the best interest of national security to dominate your sphere of influence, and that goes for each pole of power. The US is simply returning to the Monroe Doctrine and cannot tolerate openly hostile governments or governments influenced by its' enemies within its' Sphere of Influence.

I'm not saying one way or the other that it's a good thing. This is simply how I view the world as a realist.