What is the U.S. doing to deter China from attacking Taiwan?

President Biden was on his way home Tuesday from his first trip to Asia as the American leader. His last day included a summit with the three other leaders of the so-called Quad alliance: India, Japan and Australia.

"The United States must and will be a strong, steady, enduring partner in the Indo-Pacific," Mr. Biden vowed as he stood next to Japanese Prime Minister Fumio Kishida, India's Narendra Modi and Australia's freshly elected leader Anthony Albanese. All share America's concern with an expansionist and aggressive China.