In the first week of 2019, as China grabbed headlines for landing a spacecraft on the far side of the moon, a New Year's Day editorial in the nation's official military newspaper told its readers that "war preparations" should be a top priority for the year. The following day, President Xi Jinping offered a forceful reminder of what Beijing considers its most likely focus of conflict to be: Taiwan.

China's rulers have long regarded the island as a rogue province, with regaining control a point of honor for the ruling Communist Party and military alike. In a major speech on Jan. 3, Xi warned the "problem" could not be held over for another generation. While he talked primarily of "peaceful unification," he said Beijing reserves the right to use force if necessary. The speech brought a sharp rebuke from Taiwan, where residents remain strongly opposed to rejoining China, even under a Hong Kong-style "one country, two systems" deal.

Nothing in Xi's speech suggested China sees conflict as imminent. However, Xi's comments about support for peaceful "reunification" included a warning that "we do not promise to renounce the use of force and reserve the option to use all necessary measures" to prevent Taiwan's independence.