Joseph Kabila, the president of the Democratic Republic of Congo, is the latest power-hungry leader to try to extend his rule beyond his elected term, which ends next month. His obstinacy is putting an already battered country at risk.

The move could reignite civil war and destabilize the entire region, according to activists and human rights groups. There is an ominous precedent: Millions died in conflicts in Congo between 1998 and 2003 that drew in armies from neighboring countries, and the fear is that a new war will do likewise.

Under the Constitution, Mr. Kabila is supposed to vacate the presidency when his mandate runs out, on Dec. 19. But his ruling coalition and part of the opposition agreed last month to delay a presidential vote until at least April 2018, citing logistical problems in registering millions of voters. Under their plan Mr. Kabila would remain in office until that election. As part of the agreement, the country’s prime minister, Augustin Matata Ponyo, announced his resignation last week, a move that is supposed to pave the way for the appointment of a government of national unity by Mr. Kabila and opposition members who endorsed the election delay.

The main opposition bloc has fought back; more than 40 people died in street protests in September aimed at persuading Mr. Kabila to step down when his term ends. His critics say his real goal is to change the Constitution and guarantee himself a third term.