This may be why.
U.S. May Sail Through Taiwan Strait, Provoking China
Maneuver would show support for Taiwan, a hot-button issue amid U.S.-China tensions
By
Nancy A. Youssef
Oct. 20, 2018 4:39 a.m. ET
The U.S. is considering sailing ships through the Strait of Taiwan, sending a message to China about the American Military’s right to travel those and any international waters, two U.S. officials said.
The operation, which is currently in the planning stage, would include at least two ships on a multiday mission, the officials. said.
The U.S. maneuver, should it happen, comes at a time of renewed tensions between Washington and Beijing, with Taiwan, an independently governed democracy claimed by China, a hot-button issue. The sail-through would also come just after Defense Secretary Jim Mattis met with regional defense chiefs in Singapore and stressed that the U.S. would sail anywhere it wanted in international waters.
https://www.wsj.com/amp/articles/u-s-considering-sailing-through-taiwan-strait-1540024779