North Korea announced on January 6 that it conducted a successful H-bomb nuclear test of a miniaturized warhead. Prior to the announcement, sensors had detected a 5.1 magnitude seismic event at the same approximate location of North Korea’s 2013 nuclear test. Nuclear experts are continuing to analyze the data, but preliminary assessments are that North Korea did conduct its fourth nuclear test. South Korea has convened an emergency cabinet meeting to consider its response.

Seismologists can distinguish between natural earthquakes and man-made explosions since each has distinctive characteristics. The South Korean meteorological administration stated, “considering the waveform and the amplitude of the earthquake, it seems certain that it was an artificial quake. [There is] the high possibility of it being a nuke test.” An estimated size of the explosion has not been determined nor have radioactive isotopes — which would confirm a nuclear explosion — yet been detected.

Satellite imagery had shown excavation and preparatory activity at the Punggye-ri nuclear test site during the past two years. However, no indications of an imminent nuclear test were detected prior to the explosion.

North Korean leader Kim Jong-un asserted last month that his country had built a hydrogen nuclear bomb to “defend its sovereignty and the dignity of the nation.” Kim’s initial assertion about hydrogen bombs was met with expert skepticism, and it may be more likely that Pyongyang has achieved a boosted fission rather than a fusion bomb. Such a weapon would be larger than its first three nuclear tests (and the 1945 U.S. atomic weapons) but not of the magnitude from a hydrogen fusion bomb.

If confirmed, North Korea’s fourth nuclear test, particularly of an improved weapons, is a dangerous development. Coupled with ongoing development of several different missile systems, North Korea poses an increasing direct threat to the United States, South Korea, and Japan.

Experts estimate that Pyongyang currently has 10-16 nuclear weapons with potentially as many as 50-100 by 2020. North Korea has likelyalready achieved warhead miniaturization, the ability to place nuclear weapons on its medium-range missiles, and a preliminary ability to reach the continental United States with a missile.

What Washington Should Do:

Washington should be consulting with Seoul and Tokyo to devise a common response to a North Korean missile launch. The allied response should include:

Convene the UN Security Council to implement a new resolution to impose strong punitive sanctions and close loopholes, such as including Article 42 of Chapter VII of the U.N. Charter, which allows for enforcement by military means. This would authorize naval ships to intercept, board, and inspect North Korean ships suspected of transporting precluded nuclear, missile, and conventional arms, components, or technology.

to implement a new resolution to impose strong punitive sanctions and close loopholes, such as including Article 42 of Chapter VII of the U.N. Charter, which allows for enforcement by military means. This would authorize naval ships to intercept, board, and inspect North Korean ships suspected of transporting precluded nuclear, missile, and conventional arms, components, or technology. Call upon all U.N. member nations to fully implement existing U.N. resolution requirements to prevent North Korea’s procurement and export of missile-related and WMD-related items and technology and freeze the financial assets of any involved North Korean or foreign person, company, or government entity. Any violating government, business, bank, or individual should be subject to sanctions.

to prevent North Korea’s procurement and export of missile-related and WMD-related items and technology and freeze the financial assets of any involved North Korean or foreign person, company, or government entity. Any violating government, business, bank, or individual should be subject to sanctions. Adopt a more comprehensive list of prohibited items and materials. The U.N. Experts Group identified several items and materials critical to Pyongyang’s nuclear programs that should be—but have not been—added to the list of products banned for transfer to North Korea.

The U.N. Experts Group identified several items and materials critical to Pyongyang’s nuclear programs that should be—but have not been—added to the list of products banned for transfer to North Korea. Publicly identify and sanction all foreign companies, financial institutions, and governments assisting North Korea’s nuclear and missile programs . Target financial and regulatory measures against any entity suspected of helping North Korean nuclear, missile, and conventional arms; criminal activities; money laundering; or import of luxury goods.

. Target financial and regulatory measures against any entity suspected of helping North Korean nuclear, missile, and conventional arms; criminal activities; money laundering; or import of luxury goods. Impose third-party sanctions . The U.S. should penalize entities, particularly Chinese financial institutions and businesses, that trade with those on the sanctions list or export prohibited items. The U.S. should also ban financial institutions that conduct business with North Korean violators from access to the U.S. financial network.

. The U.S. should penalize entities, particularly Chinese financial institutions and businesses, that trade with those on the sanctions list or export prohibited items. The U.S. should also ban financial institutions that conduct business with North Korean violators from access to the U.S. financial network. Augment U.S. sanctions. President Obama’s assertion that North Korea is the most heavily sanctioned country in the world is simply not true. Washington has targeted fewer North Korean entities than those of the Balkans, Burma, Cuba, Iran, and Zimbabwe. The U.S. has targeted more than twice as many Zimbabwean entities than North Korean. Nor has Washington designated North Korea as a primary money-laundering concern as it did Iran and Burma.

For its part, South Korea should:

Resume propaganda broadcasts along the DMZ , dramatically increasing broadcasting into North Korea including assessing the viability of using drones along the North’s coasts, and removing any restrictions on non-government organizations sending information leaflets via balloons into North Korea. The August land mine crisis showed the sensitivity of the Kim Jong Un regime to information psychological operations.

, dramatically increasing broadcasting into North Korea including assessing the viability of using drones along the North’s coasts, and removing any restrictions on non-government organizations sending information leaflets via balloons into North Korea. The August land mine crisis showed the sensitivity of the Kim Jong Un regime to information psychological operations. Sever its involvement in the Kaesong industrial park. The joint business venture was always more on political than economic objectives. Since its inception, the Kaesong venture failed to achieve its primary objective of inducing economic and political reform in North Korea and moderating the regime’s belligerent foreign policy.

The joint business venture was always more on political than economic objectives. Since its inception, the Kaesong venture failed to achieve its primary objective of inducing economic and political reform in North Korea and moderating the regime’s belligerent foreign policy. Request U.S. deployment of the THAAD missile defense system. South Korea’s indigenous missile defense system is insufficient to defend against North Korea’s growing nuclear and missile threat.

North Korea’s nuclear test is a serious and irreparable violation of numerous UN Security Council resolutions. It reflects Pyongyang’s continued pursuit of its prohibited nuclear weapons programs in open defiance of the international community despite countless attempts by the U.S. and its allies to reach a diplomatic resolution.

The regime has repeatedly asserted it has no intention of ever abandoning its nuclear weapons, even revising its constitution to enshrine itself as a nuclear weapons state. North Korea’s continuing improvement and augmentation of its nuclear arsenal threatens the United States and its allies.

It is time for the Obama Administration to abandon its policy of timid incrementalism and fully implement existing U.S. laws by imposing stronger sanctions on North Korea and work with Congress to determine additional measures.

This piece also appeared at the Heritage Foundation

Main picture: E. Lafforgue