Will Russia Be Able To Defend Herself Against Chinese Invasion?

This is hilarious. China's agriculture is fed almost exclusively by five major rivers. Five groundbursts at the source contaminates the water, which contaminates the animals and produce downstream. No new agricultural production is possible. Now then, China has about 120 major cities, hit each of these with say five devices each (the R-36M ICBM Mods 2, 4, and 6 each carry a MIRV with up to ten warheads each with a yield of 550-750kT, it would take about sixty such missiles to pull of this second stage of the proposed operation, Russia has 346 available) and you would see the destruction of every major port and highway nexus in China. What does this do? Any food the Chinese have stockpiled can't be moved since the major roads and railways are out and they can't import food since the dockyards no longer exist to get the food off the ship decks. China doesn't want anything to do with fighting a nuclear nation. Can Russia defend itself against a Chinese invasion? Can China sustain such an operation when she has two billion people starving to death and dehydrating back home?