North Korean leader Kim Jong Un. (Korean Central News Agency/Reuters)

ONE SCHOOL of North Korea experts has been arguing for some time that sanctions will never induce the isolated regime of Kim Jong Un to give up its nuclear weapons nor its race to develop intercontinental ballistic missiles that could carry them to the United States. A good answer is that while they might be right, sanctions are still the best available option — and unlike others, such as negotiations with the regime, they have never been given a robust try. Fortunately, that may be about to change.

After waiting in vain for China to apply serious pressure to the Pyongyang regime following President Trump’s first meeting with Xi Jinping, the administration is readying sanctions against a number of Chinese companies and banks that do business with North Korea, a senior administration official said this week. A sanctions bill on its way through Congress mandates additional steps against North Korean shipping, countries that evade U.N. sanctions and those that employ the slave laborers whom the regime exports to other countries. Still-tougher measures are in a pending Senate bill developed by Maryland Democrat Chris Van Hollen.

If the administration aggressively and consistently exploits the new authorities — an open question, given the endless chaos in the White House and gaping personnel holes at the State Department — it might be able, over time, to cut off a substantial part of the flows of hard currency that last year allowed North Korea to increase its trade by nearly 5 percent and that financed $1.7 billion in imports from China in the first half of 2017.

The problem is a lack of time. Even successful sanctions campaigns, including that which induced Iran to bargain over its nuclear program, can take years to produce results — and the time North Korea may need to acquire the ability to threaten a nuclear attack on the U.S. homeland appears to be rapidly shrinking. The Post reported Tuesday that U.S. intelligence agencies have concluded the Kim regime could produce a missile that could reach the U.S. homeland with an atomic warhead in a year, years faster than previously estimated. On Friday, the regime carried out a new test of what appeared to be a long-range ICBM, the second this month.

Not surprisingly, both the administration and outside experts are debating other options. CIA Director Mike Pompeo recently hinted at a strategy to “separate” the Kim regime from its weapons. If that means regime change, it would require far greater cooperation from a Chinese government that so far has been unwilling to seriously pressure its neighbor. Some analysts suggest the United States should take up a Russian-Chinese proposal for a freeze on North Korean missile and nuclear tests in exchange for a halt to U.S.-South Korean military exercises. But history shows that any North Korean commitment to a freeze would be temporary and unreliable, while Washington’s agreement to the deal could introduce a permanent crack into its alliance with South Korea.

One helpful proposal comes from the State Department’s former human rights chief, Tom Malinowski, who wrote in a Politico essay that the United States should ramp up efforts to provide the North Korean people with information, including about the far freer and more prosperous lives of South Koreans. Political change in North Korea forced by its own citizens, he says, is more likely than denuclearization by the current regime. That clear-eyed but ultimately hopeful forecast strikes us as sensible.