Behind closed doors in Beijing this week, China’s top officials are meeting to refine a plan to secure its strength in a turbulent world. But two great questions hang over the nation’s future, even if no one at the meeting dares raise them: How long will Xi Jinping rule, and who will replace him when he is gone?

Xi has led China for 13 years, amassing dominance to a degree unseen since Mao Zedong. He has shown no sign of wanting to step down. Yet his longevity at the top could, if mismanaged, sow the seeds of political turbulence: He has neither an heir apparent nor a clear timetable for designating one.

With each year that he stays in office, uncertainty deepens about who would step in if, say, his health failed, and whether the new leader would stick to or soften Xi’s hard-line course.