There are countries in world that have grown their populations to levels that cannot be supported locally. For eg. North Africa and Middle east, etc. can't grow enough food for their local population, globalization has enabled them to do trade at a large level and hence ensure supply of food. With all supply chains disrupted with deglobalization, expect famines in such countries. Same with other imported stuff as well.
Famines will = Invasions.
Say food is fraudulently made too expensive in an effort to reward thieves. Perhaps caused to be in short supply by man made manipulation. What will happen? Probably, like greed and banking fraud before, it will first cause immigrant/migrant swarms, then INVASIONS of nations that have lots of wealth, good farmland and agricultural productive capacity.
USA, EU, UK, Canada, Nz, and India all have migrants a plenty. You guys love the Bangladeshi migrants in India?
Already the invasions begin. Weak no ally break basket Ukraine got HIT first.
Who else has lots of farmland and food? India, USA, France, South Africa? South American nations? Parts of Russia? Where can you survive if modern society breaks down?
World War Z? They are the people with no food and no wealth thus in a way they could be considered the dead.