The usual answer — a nuclear-free Korean Peninsula — is wrong. There is no strategy of inducement or coercion that can persuade Pyongyang to relinquish an arsenal that is both its best defense against coercion and its best way to extort benefits from the West.

A more recent answer — an agreement by the North to freeze its nuclear and missile programs in place in exchange for United States concessions, such as the suspension of joint American-South Korean military exercises — is also wrong. The North will inevitably violate it, but the agreement will persuade Pyongyang and Beijing that they can drive a deep wedge between Washington and Seoul.

The right answer is that we want the Kim regime out of North Korea. It isn’t the nukes that ought mainly to worry us. It’s the hands that hold them.

Critics of a regime-change strategy note that the only way it could be brought about — short of war, coup or uprising — is with China’s acquiescence. Beijing could end the flow of diesel and gas to Pyongyang, invite Kim for a parley, and permanently ensconce him in the guesthouse that once housed Cambodia’s deposed Prince Sihanouk. Instead, Beijing prefers to maintain the North as a buffer state, a diplomatic bargaining chip and a tool for indirectly threatening the United States.

Until recently, Beijing paid no price for this behavior. It went along with ineffectual United Nations sanctions but enforced them lackadaisically, if at all. That started to change only last year, when the Obama administration charged four Chinese individuals and a Chinese company with laundering funds for the North.

The good news is that the Trump administration has picked up the theme with a new round of sanctions on Chinese entities. It shouldn’t stop there. As Anthony Ruggiero of the Foundation for Defense of Democracies notes, the goal should be to push Chinese banks and businesses to make a fundamental choice between trading with Pyongyang and having access to dollars. The market will reach its own verdict. Last month’s billion-dollar United States arms sale to Taiwan, along with United States Navy challenges to Chinese maritime claims in the South China Sea, should also send the message that the administration will exact a price on Beijing for ignoring American security interests.