The deaths of 300 million people should not be taken so lightly as to their effects on the world economy either. China had a hlaf-half-dozen of the CSS-2 missiles actually ready to use, we thought a *test* was at least 18 months away. Moscow shot down the hundreds of fake-signal drones fired at the city only to miss one of the two real target, hence why Moscow, Omsk, Novosibersk, Astrakhan, and Stalingrad were annhilated. Leningrad/St Petersburg only survived by being out of range, even then it came under threat from Chinese long-rage aircraft out of Urumqi on one-way trips. With Moscow offline the Warsaw Pact shattered and the Commonwealth was soon reborn (Poland, Ukraine, Baltic States, Czechloslovakia) along with the Balkan Federal Union (Romania, Bulgaria, Yugoslavia). Russia itself shattered into the Remnant USSR east of the OB and the New Empire out of Siberia.
But China regressed into a warlord zone, for five years China had three dozen 'legitimate' goverment while North Koreans were eating their own dead for a while. Taiwan survived only to become 'seamstress and junkyard of Asia' before Pakistan and India had their peace talks. Hard to believe that they would make a permanent peace the following year, or that Arafat would be the one to mediate it, but the war made a lot of people sit up and take notice. Hell, even Vietnam might have had a few more years of American involvement if not for the Peace of Paris in late 1970.
I am fairly sure the South Asian Trade Community would not be a factor, but then who would have dreamt of a common currency from Baghdad to Brunei forty years ago? Or even fifteen? The USSR was doing well enough to make the 21st century, especially if the microelectronics revolution proceeds on pace starting in 1980. Maybe the Space Race actually goes on instead of stalling out too