Re: "War happens when one party thinks that the other party is weak enough to be attacked."

You're almost there.

Now just integrate 1) industrial complexes that form via a handful of greedy-psychopathic individuals who lobby politicians into "power" to help with regulatory capture, and 2) authoritarian types who become or are groomed to become politicians in positions of "power" - of control of policy decisions - which are the two sides of the fascism coin.

Next integrate theatre, manufactured consent, propaganda and manufactured war - where bad actors on "both sides" simply want to maintain control and be able to pillage the resources (and rape and murder as they please) of their land - and so they come to a "gentlemen's" agreement behind closed doors where they promise to leave their upper hierarchy alone - but destroy

It's divide and conquer, distract and conquer; perhaps with a sprinkling of cloak and dagger, bait and switch, and other idioms may be fitting.

Who benefits in this scenario? The military industrial complex, most certainly, other industrial complexes, but more so the tyrants and tyrant wannabes.

The tyrants want a sick and weakened population so that they can't be held accountable, are less of a resistance against their blindly indoctrinated militaries - or outright genocidal militaries who over many decades to many generations have fomented a hate for a specific group - where they see them as less than human, and therefore anything against them is justified; such falsehoods always being believed by a very thin veil of many shallow-thin threads of propaganda narrative talking points - manifesting into reality simply by repeating the points, keeping the mind's attention enough and filling in enough logic to make most undeveloped-stunted minds feel like it's solid enough, and therefore a truthful reality; with the indoctrinated ideologue not critically thinking through each point, rather they are emotionally knee-jerk reactive and already have been trained what the counterargument to blurt out, to parrot, is - quick, easily memorable one liners.

There of course will be useful targets that the dominant cohort-coalition of tyrants - the establishment division as I call them, globalist elites as others do - perhaps obvious dictators or tyrants in their land, however they aren't toeing the line of the dominant group - and therefore that tyrant going it alone is a threat to the "power" - of the coalition's wet dream of world domination and a global totalitarian state;

Russia is likely being used as a wedge, and Palestine now as well - both with the potential to ignite WW3. However fear mongering with climate alarmism appears to be their fallback plan they're moving forward with in parallel if they can't get the systems moving towards WW3. If successful then can draft and force anyone strong remaining into the meat grinder, so they are no longer a threat to local control and corruption.

Re: "... and unfortunately, that's where the West has a massive problem. Almost eighty years without an existential threat."

Once again almost there. A weakened population is easier to control, which is perhaps just a coincidence of industrial complexes maximizing profits - but it helps accelerate towards a fascist state. Placating the population, distracting them with entertainment, with low quality numbing foods, while squeezing as much quality of life out of them as possible by indoctrinating them into narrow educational channels; see book "The Unsettling of America: Culture “& Agriculture to understand what well-rounded, highly competent development and intelligence looks like.

“Commercial conquest is far more thorough and final than military defeat” - The Unsettling of America book.

Capture the means of production, the economic-monetary system, and then simply economically suffocate any resistance by via Social Credit score system and mechanisms, to turn off the tap down low enough for political dissidents-opposition-resistance to the tyranny; or for example only allow government positions say in a “free” public health care system, education, and military institutions — where you’re only given a salary from the government — cranking up costs of living for all of society, but if you have a government job — they can continue to print as much money as they need to fund and keep those toeing their line afloat while the general population is allowed to, if not pushed under faster, to drown.

It’s party to 5th generation - psychological - warfare where you want to do the most subtle things in order to not spook the herd, so that it doesn’t react and flee from you - or come after you for the valid threat that “you” are.