Japan’s Prime Minister Sanae Takaichi sparked debate and provoked China’s anger by hinting that a Chinese move on Taiwan could spur a Japanese military response. In the wake of her remark, she received a phone call from U.S. President Donald Trump, underlining the magnitude of the diplomatic situation.

President Trump announced his opposition this week to the sale of Pittsburgh-based U.S. Steel to a Japanese company, signaling a significant shift in his stance on the matter. This development could have far-reaching implications for the proposed deal and international trade relations.