North Korea’s nuclear test last Tuesday has the makings of an epochal event — unless Washington and Seoul shape up and deal Kim Jong Un’s regime a substantial, although nonmilitary, blow.

Pyongyang’s blast, two months after its first successful intercontinental ballistic missile test in five tries since 1998, and the regime’s demonstrated progress in long-range missile technology are propelling the totalitarian nation toward bona fide nuclear capability. With that comes the capability to provoke its neighbors with impunity and to extort funds, fuel, political legitimacy and even concessions in U.S. and South Korean military forces and readiness. Another nuclear test, especially of a uranium bomb, would mark a turning point.

The Obama administration and South Korean President-elect Park Geun Hye must accept that policies of intermittent dialogue and status quo maintenance have failed. For too long, Washington and Seoul have been possessed by a blurry paradigm of “appeasement or war,” effectively depriving themselves of a credible, nonmilitary deterrent if Pyongyang were to continue its external threats and internal repression.

Washington and Seoul should target Pyongyang’s greatest points of vulnerability: the Kim regime’s overdependence on its “palace economy,” and its systematic oppression of its people through a vast network of gulags and an omnipresent secret police force.

An international network of shadowy officials, banks and front companies sustains the North’s ruling clan, military and internal security forces — even though the North’s national economy collapsed nearly 20 years ago with the loss of Soviet subsidies — and it enables the regime’s dependence on nuclear blackmail and illicit earnings. The regime’s overdependence on such financial dealings makes it particularly vulnerable to U.S. tools designed to counter international money-laundering.

Washington has long had the ability to enforce financial regulatory measures against North Korea’s illicit activities and proliferation of weapons of mass destruction; it has lacked the political will to do so. U.S. officials should immediately strengthen sanctions against North Korean banks, businesses and individuals that illegally finance Pyongyang or help the regime commingle and conceal its black-market income within “legitimate” trade.

To this end, the Treasury Department should designate the North Korean government a “money-laundering concern” under Section 311 of the Patriot Act.

This would allow the Treasury to require U.S. banks to take precautionary measures against all foreign entities and governments linked to the sanctioned target. Being blocked from accessing the U.S. financial system would be a strong deterrent against abetting Pyongyang’s illicit activities.

President Barack Obama could also press allied governments to apply corresponding measures to third-country banks, businesses and nationals that engage Pyongyang in international financial transactions. Such actions would isolate Pyongyang from the international financial system and sever several of the regime’s main streams of revenue. At the same time, the United States should state clearly that it will provide humanitarian aid to the North Korean people if it can ensure that the aid reaches the needy.

Critically, these measures can be enforced without Chinese cooperation or even in the face of Chinese obstruction. Moreover, under Executive Orders 13,382 and 13,551, the U.S. can freeze the assets of Chinese and other third-country entities suspected of helping North Korea’s proliferation activities.

If Washington sustains this aggressive policy, the accumulated pressure would most likely minimize Chinese obfuscation and may even induce the pragmatic leadership in Beijing to cooperate in protecting the integrity of the international financial system.

Such measures, if sustained, would also drive away international entities that, intentionally or not, undermine United Nations-mandated sanctions. This credible threat of devastating consequences for the Kim regime gives U.S. and South Korean diplomats the leverage to secure a verifiable disarmament agreement and a disincentive for Pyongyang to approach denuclearization talks with the willful deceit it has shown over the past 20 years.

Concurrently Pyongyang’s crimes against humanity and the information blockade that conceals them should be targeted. Last month, U.N. human rights chief Navi Pillay called for an “in-depth inquiry” into “one of the worst — but least understood and reported — human rights situations in the world.” Washington and Seoul should draw global attention to the North’s horrific prison camps and obscene squandering of wealth while citizens classified as “wavering” or “hostile” starve.

Free societies should vastly increase support for radio broadcasts and other efforts to transmit information into North Korea. As the sole legitimate representative government on the peninsula, South Korea should take the lead in this global human rights campaign. Park Geun Hye should also reinforce programs that facilitate resettlement of North Korean defectors.

The more that democratic societies recognize the North Korean regime as a threat to humanity, not just an idiosyncratic abstraction, the less they will allow their leaders to resort to politically expedient measures regarding future provocations by Pyongyang or to indefinitely postpone Korean reunification.

Faced with this two-pronged strategy, the Kim regime is likely, in the near term, to resort to further provocations. In time, however, it is far more likely to yield to pressure than to lash out in full military force, for the North Korean leadership entertains no suicidal impulses.

Obama and Park should realize that only a credible deterrent will compel Pyongyang to negotiate disarmament in good faith and to relax — even if in increments — its totalitarian control of its populace.

The sooner and more palpable a threat the cash-strapped Kim regime is exposed to, and the more that downtrodden North Koreans are exposed to the outside world, the sooner a safer, more humane North Korea will become a reality.

Sung Yoon Lee is an assistant professor of Korean studies at Tufts University’s Fletcher School of Law and Diplomacy Joshua Stanton blogs at One Free Korea (freekorea.us).