The president has already done so seven times, like all her predecessors in Taiwan since 1990. And each time there have been protests from Beijing, including a naval maneuver in the Taiwan Straits with live ammunition in the mid-1990s. But Tsai Ing-wen’s eighth visit to the United States has the potential to spark a stronger reaction. Although the Americans emphasize, as in the past, that the stay of the head of government of the breakaway island republic claimed by China is no more than a transit.