The outgoing US ambassador to the United Nations says she watched America's leadership diminish in the world during Donald Trump's first presidency and China fill the vacuum. Linda Thomas-Greenfield is warning that if it happens again during Trump's second term, adversaries will move in anew. In a wide-ranging interview with The Associated Press, Thomas-Greenfield said during Joe Biden's presidency, the United States again engaged with the world, rebuilt alliances and reestablished America's leadership. That is the gift that we hand over to the next administration, she said, and I hope that they will accept that gift in the spirit in which it is being given to them. Advice to Trump's choice for UN ambassador In a brief meeting with Trump's nominee, Rep. Elise Stefanik of New York, Thomas-Greenfield told her that the UN is important, and that it is important that we not cede any space to our adversaries. Those rivals will change the rules of the road," she warned. "And so, US ...