Some 25 million North Koreans, including 80,000 to 120,000 prisoners in slave-labor camps, would be released from the grip of one of the world’s most repressive regimes. The states that Pyongyang threatens would also be relieved: South Korea, which today is at risk of commando or conventional military operations from the North; Japan, which is within range of missile strikes; the United States, which worries that it will get dragged into a conventional war on the peninsula, or that Pyongyang may sell off nuclear material.

Even China, a putative ally of the Kim regime, would benefit from its fall: Beijing would no longer have to supply the North with fuel, food and other goods, and pay the diplomatic cost of supporting a pariah state.

Even more significant would be the economic opportunities for South Korea. The total bill for rebuilding North Korea and integrating it with the South could reach $2 trillion — more even than the cost of Germany’s reunification after the Cold War, estimated at $1.9 trillion. But some of that expense would be offset by immediate savings on South Korea’s defense budget, some $32 billion this year alone.