Not sure this is defined the same way but 10% seems pretty common even without war. Even India is apparently already worse than that [1]. Who would you blame for starving the Indians?
According to the IPC, "acute malnutrition is a form of malnutrition that occurs when an individual suffers from current, severe nutritional restrictions, a recent bout of illness, inappropriate childcare practices or, more often, a combination of these factors. It is characterised by extreme weight loss, resulting in low weight for height, and/or bilateral oedema, and, in its severe form, can lead to death." [1].
Your chart measures undernourishment, which the FAO defines relative to "how many calories [one] need[s] to maintain a healthy life" [2].
This solves the problem you were devil's advocating. And we don't need to theorize about other numbers.