For the past two weeks Chinese and American negotiators have been locked in talks in Beijing and Washington to end their trade conflict before the deadline of March 1st......Don't be distracted by mind-numbing details on soybean imports and car-joint ventures. At stake is one of the 21st century's most consequential issues: the trajectory of China's $ 14trn economy.
Added from OP's comment:
I know the basic meanings of "at stake", but I find it difficult to decide which best fits in the context. I thinking both "under discussion" and "in the process of being determined as a positive or negative outcome" make sense. But translators from "The Economist" magazine decided on "what matters most". I'm confused...