Antonio Guterres addresses the 80th United Nations General Assembly at UN headquarters in New York City on Tuesday. Reuters photoUnited Nations– With global peace and progress under siege, the United Nations chief challenged world leaders Tuesday to choose a future where the rule of law triumphs over raw power and where nations come together rather than scramble for self-interests. One of them had stopped unexpectedly as he and first lady Melania Trump were riding it toward the Assembly hall. The US president’s “America First” credo has always been a tricky fit with the UN’s commitment to global-scale shared decision-making. Gaza already has seized attention at the General Assembly.