This is basically correct, but it's shaped by a few historic factors (note I don't necessarily agree with all of these, just putting them out there):

1 - The U.S. was almost constantly engaged in a domestic or near-territorial war of some kind from its founding until quite a few years into the 20th century. [1] During the time period the U.S. massively expanded, strengthened itself by defining borders and internally squashing various kinds of rebellions. Since then, the U.S. has basically been at war continuously. America is, believe it or not, a kind of warrior culture.

2 - The U.S. usually is able to claim some kind of victory out of most of its military endeavors. Thus military engagement is seen as a tempting, low risk, policy tool. The historic level of military success the U.S. enjoys is almost unprecedented in history. By selectively choosing engagements it knows it can win, the U.S. can continue the development of this legend.

3 - Domestically, Americans tend to think of our military actions as generally being benevolent in nature (e.g. stopping communism, fighting nazis, freeing subjugated peoples). The outstanding economic success of many countries who's soil we fought on and then built strong alliances with (Germany, Korea, Japan, France, etc.) feeds into this mythos. The post-war alliances we've formed help to "encourage us" to get involved.

4 - The modern state of the world's powers, an outcome of WWII, is one in which the U.S. is militarily uncontested by any power on the planet. The relatively few conflict deaths post-WW2 [2] seems to imply that U.S. military dominance brings peace, stability and prosperity and helps drive the notion of the Pax Americana [3]

5 - The failures and generally poor outcomes in countries under other major power's influences and policies feeds into this as well. For example, at one point a majority of the land-mass on the planet was engaged in Communism, under Russian control (as the U.S.S.R.) or influence. Despite access to tremendous natural resources (and short lived modernization programs), the Communist countries failed to produce economic successes and were often engaged in tremendously damaging internal conflicts.

6 - Pax Americana is viewed by Americans as a "good thing". Even though Americans don't view themselves as expansionist colonial powers, they view the expansion of the Pax via the export of American culture and influence as a good thing. This implies then that the current state of American dominance is a good thing, and that anything that even looks like it might be vectoring towards threatening that status quo (e.g. belligerent Russia, rising China, trouble on Allied borders etc.) needs to be aggressively halted or stopped.

American policy is generally framed as #6, with 1-5 as a supporting framework. If thought of on purely military terms, American military expenditures and actions can't really be rationalized. If thought of on terms of #6 they make all the sense in the world. There's a lot of self-filtering involved too. Americans ignore the failures and negatives surrounding military action, and the various excesses that come with pouring something like half of the government's discretionary funding into the DoD.

But the illusion of continued threats is one that we've created in order to continue on justifying with what we generally believe is a better world under our influence than the one that existed before.

You can hear most of this echoed when fairly sensible ideas like "maybe Americans should pull out of Europe and let the Europeans, who are economically and technologically able, to deal with defense needs for themselves" are floated. Responses (even from Europeans) are often along the lines of "no, European countries can't be trusted to cooperate well enough" or "remember the last time Europe was left to sort things out?" and so on.

This also ignores entire continents like Africa, where Americans just simply can't figure out what to do at all. Our national notion towards Africa is basically to just ignore the continent and work on Middle-East containment instead. These days when Africa comes up at all, it's usually in terms of growing Chinese influence.

1 - https://en.wikipedia.org/wiki/List_of_wars_involving_the_Uni...

2 - https://vimeo.com/128373915

3 - https://en.wikipedia.org/wiki/Pax_Americana