In “The Avoidable War: The Dangers of a Catastrophic Conflict Between the US and Xi Jinping’s China,” Kevin Rudd, a former prime minister of Australia and a longtime scholar of China, imagines 10 distinct plotlines, many revolving around the fate of Taiwan. For instance, what if China seeks to take the island by force and Washington opts to not respond? That would be America’s “Munich moment,” Rudd writes, eviscerating any American moral authority. Even worse would be the United States reacting with military force but then losing the fight, which…