I’ll answer the “why would it now lead to disaster” part, and by shuffling names, places, & contexts around I believe much of that can be obliquely backported to the same question with respect to runup to the world wars of yore.
USA’s multi-decade cultural imperialism and dogged pursuit of economic hegemony led to it imposing itself as a global barometer and gatekeeper (despite being famously incompetent at both). The upshot is that now, even though philosophically it would be wonderful for the US to finally stop enforcing a petrodollar-driven serfdom on so much of the world in the name of “infinite (US economic) expansion”, pragmatically speaking a magical and abrupt “pull out” would be wildly irresponsible, much like yanking an arrow out of a wound in the direction from which it entered (causing a Jackson Pollock’s worth of collateral damage). That would largely be because the sudden power vacuum would not be able to be filled in time by other countries (who are under-resourced due to aforementioned hegemonic squeezing), leaving not enough people to “not tolerate the intolerant”, leading to explosive expansion of the “ignorant bullies masquerading as politicians” brigade (not unlike Hitler’s opportunistic power-grab while the politicians who should have been the ballwark against him hubristically sat on their hands). See: https://www.ournationalconversation.org/post/explaining-the-paradox-of-tolerance
(NOTE: I am not a doctor, nutritionist, etc - just someone who has learned a lot of lessons the hard way and likes to share). Without challenging the focus of these stats, I’d like to add two interrelated side-notes (from decades of being professionally physically active, and then decades of being professionally deskbound and too burnt out to move in my spare time, and then getting it mostly back under control later): (1) If you have reached the point where you have long-term struggled with losing weight then - unless you are a very rare exception - changing diet alone will likely not be enough because (2) the steepest but most important curve is “reprogramming your metabolism”. One of the most common psychological obstacles I see people hit after years of sedentary living is naively changing only what they eat and getting disappointed when their body doesn’t magically “change gears” by itself. The second most common obstacle I see (when people do also start moving their body too) is “counting kilos/pounds” and giving up in frustration when the numbers don’t go down straight away, or even go up. When you do “any old exercise” you burn energy while you exercise (which is of course better than not doing any, and helps with aerobic/cardio/psychological fitness too) but beyond that one of the best secrets to serious body transformation is to build muscle (including the women, and not necessarily to a “bodybuilding” degree - a lot of muscle building happens before the “looking jacked” phase). When you do that the increased muscle burns more energy all day and night, not just during the exercise - it reprograms your metabolism. Even better, the longer you do it it doesn’t just “change gears” in those moments/days, it teaches your body to become better at “changing gears” in the future. Eventually (unless you have a medical condition, etc) the excess fat burns itself off in service of your body’s new functional requirements. Another thing that surprises many is how little resistance training is actually needed for a good baseline to start with (for many people three “adequate but not crazy” workouts per week is enough to see steady progress). BUT a big confusion happens for people weighing themselves all the time - muscle is more dense than fat so there is a good chance if doing it the right (emotionally & financially sustainable) way your overall weight might appear to plateau for ages (or even increase) at first while the increase in dense muscle offsets the loss of sparse fat. I suggest for “tracking weight/fat loss” in most typical cases do so indirectly, not by naively counting loss of overall kilos (of fat, muscle, bones, organs, tendons, ligaments, and so on combined). Regarding diet (especially when exercising) some good rules of thumb are to ensure a broad spread of micro nutrients by shopping for various fruits, veges, nuts, seeds, etc (including semi-regularly surprising yourself with things you usually wouldn’t buy to cover the edge-case micros), ensure a good balance of macro nutrients (often the “40 30 30” guide is near enough - 40% carbs, 30% protein, 30% fats - but when strong muscle-building you will need higher amount of protein, covering broad amino acid spectrum), reduce processed foods which are “energy dense” (a euphemism for “nutrient sparse”), keep hydrated, get sun (or other source of vitamin D) every day, reduce sources of stress (stress-addiction to adrenaline and cortisol is real and devastating to your body, and highly addictive if you continue for too long). The most important part is - whatever positive changes you achieve - you need to win the mind-game by making them part of your unquestioning routine, not a novelty that you try to keep kicking down the road. The best equivalent I can think of for this is brushing your teeth - most people find it boring but “just do it” without pondering “will I manage to brush my teeth today”. Internalise the other changes the way you brush your teeth.