Should Comparative Advantage be disregarded on the issue of food necessities?

Japan has more reasons to do so,such as a more balance between urban and rural area,to keep environment in rural area, and for the health of the nation. And most of food exporting countries will have measures to protect domestic market first,including buffer stock and export premium. Only the rest will go to the world market. And in the case of food surplus,it has to dump the world food market at any cost.