Would starvation be a problem? Don't most countries have food reserves for these cases? At least enough food for one season?
No, nations do not have the means to feed their constituents in a nation ending disaster. It's easy to move food from Florida to California in a state sized crises, but the logistics of maintaining a just in case food supply for hundreds of millions distributed around the country? It's a safer bet to assume you'd die in the disaster than to convince people to plan for the future.