[upbeat_general]

Not a war crime, China has plenty of agriculture.

See the Cuban missile crisis. It is an act of war but certainly not as escalatory as direct attack.

[pembrook]

Chinese agriculture is heavily dependent on fertilizer and energy imports. A blockade would easily result in famine.

In fact the history of China is just constant famines.

[geysersam]

Is the history of China any more famine stricken than any other region if the world? In recent history (last two centuries) maybe, but before that? Typically you don't become the worlds most populous country by having frequent famines.