I think it would be similar with the "cold war" time: Both countries are too big and have too many weapons, so if they would have an open war, that would force both sides to use all their weapons, it would simply end with the world doomed because of nuclear fallout ... Because of both countries knowing that neither of them would survive an open war without critical losses, it would end with "secret wars": Industry spying, economical fighting, diplomatic arguing, unofficial supporting of illegal terror groups, ... until one of the country finally is economical destroyed.
As example for that economical wars: The US government had deals with the arabian oil countries, and engaged them to produce much more oil then needed, because of that the price for oil and similar ressources were decreasing. Around that time russias export were about to 80% export of similar ressources like gas and oil. So a lower price for that ressources was like a bomb for the russian economy.
I think in the end, the US would win, because of the one child politic, China already has problems to find enough workcraft and will have economical misadvantages, because large parts of their people will be to old to strenghten their economy.
What would happen if all kind of television suddenly wouldn´t work anymore?