Amid the mounting signs of distress, a series of policies could help to minimize human suffering. However, most would require a considerable degree of international cooperation, which might be difficult to achieve in the current environment.
I'm really wondering if Orwell's prediction from almost a century ago, that the world would devolve into three major blocks continually at war with each other, each exercising authoritarian control over their domestic populations, isn't on the verge of becoming a reality. It appears that both Russian and American political leaders view the conflict in Ukraine as beneficial to their own domestic political interests, for example - and China is not yet involved, but what if there's a war in Asia, i.e. Taiwan? The global South sits outside this picture, so maybe there's some hope there.
As far as practical matters, there are a lot of approaches to ensuring local food supplies. Victory gardens were a thing in WWII for example. Also, there are several known vegetarian mixtures that give full amino acid profiles, such as the corn-beans-squash mix of pre-Colombian agriculture in NAmerica, or rice-bean bases of SAsia, etc. Recycling nutrients via effective composting also reduces the need for fertilizer imports.
Avoiding reliance on global supply chains is going to become very important if current trends continue, in any case.