Self sufficiency is what keeps you from starving when trade has a down turn. The US is a net food exporter so even if the tech industry implodes, the US still has food for its home market, and can raise trade barriers to keep it at home.

On the other hand countries that must import food, suffer greatly when there’s any economic shock. Basic food stocks can double or tripe in price due to inflation affecting imports most strongly. And the country is trapped: it must export in order to get money to buy food, however demand is already down. Add to that that many counties run on credit, so failing an import/export balance leads to additional debt, increased inflation, and a vicious spiral to economic ruin.