Will an uptick in diplomacy between China and the United States set meaningful "guardrails" for the competition between the world's two largest economies? First it was the defense ministers' meeting in Singapore. Then the two countries' senior economic officials talked about tariffs among other things. And most recently, Chinese foreign minister Wang Yi and U.S. Secretary of State Antony Blinken had a five-hour meeting. What concrete outcomes have come out of these China-U.S. engagements?