The reference was to Commodore Perry.
It would appear that General Kenny is stating the current population is 73,000,000 and when it was a closed society living on domestic production the law required a population of 30,000,000. So he is making a point of what happens as they stop the imports.
Just caught me attention that there was a law regarding population. Also the Chinese had similar laws in the 60’s, a cultural thing? It has happened in the past and could very easily happen in the future even here.