Have tariffs ever worked? (asking for a mate)

(COMBO) This combination of pictures created on May 14, 2020 shows recent portraits of China's President Xi Jinping (L) and US President Donald Trump.. US President Donald Trump said on May 14, 2020, he is no mood to speak with China's Xi Jinping, warning darkly he might cut off ties with the rival superpower over its handling of the coronavirus pandemic. "I have a very good relationship, but I just -- right now I don't want to speak to him," Trump told Fox Business. (Photo by IORI SAGISAWA and MANDEL NGAN / various sources / AFP) (Photo by IORI SAGISAWAMANDEL NGAN/POOL/AFP/AFP via Getty Images)