For decades, Taiwan has looked to its east coast as a safe haven to survive a Chinese invasion until allies, particularly the U.S., can arrive to assist. In the east, Taiwan’s rugged mountain terrain also helps create a natural shield in the event of an attack. But China’s PLA activity on the island’s east has thrown that strategy into question.br br WSJ takes a look at how serious China’s threats to Taiwan’s east coast are and explores whether the island needs to change its defense strategy.br br 0:00 Taiwan’s current strategybr 1:38 The problembr 4:15 Taiwan’s reliance on alliesbr br News Explainersbr Some days the high-speed news cycle can bring more questions than answers. WSJ’s news explainers break down the day's biggest stories into bite-size pieces to help you make sense of the news.