The Kang Nam, a two-thousand ton North Korean freighter, is powering towards Southeast Asia. An eight-thousand ton American destroyer, the John S. McCain, trails behind it. As the two-ship mobile standoff crawls along the east coast of Asia, telephones have been ringing in Washington, Seoul, and Tokyo, as the leaders of the U.S., South Korea, and Japan scramble for a strategy to confront North Korea's weapons smuggling operations.

According to a South Korean intelligence report, the Kang Nam likely carries a payload of missile components, probably en route to the dictatorship of Myanmar. A recent U.N. Security Council resolution calls on member nations to inspect vessels "with the consent of the flag State" if they have information that provides "reasonable grounds" to believe that the cargo is prohibited.

The "consent" clause was added at the insistence of China and Russia. If the flag State does not consent to inspection, the resolution calls on the flag State to "direct the vessel to proceed to an appropriate and convenient port for the required inspection by the local authorities." North Korea will not consent to inspection, and if the ship reaches Myanmar, the authorities there will not adhere to the U.N. resolution. So if the U.S. wishes to interfere with the shipment, it must either forcibly board the Kang Nam or else force it to dock in an allied nation, like Singapore. Either action would go beyond those called for in the resolution.

North Korea has previously stated that it would treat interception of its ships as an "act of war" and promised "a 100- or 1,000-fold retaliation with merciless military strike." It has threatened both South Korea and the United States, and is reportedly planning a July 4th missile test that could reach Hawaii. While North Korea would be unlikely to inflict much damage on U.S. soil, it's massive army, missile arsenal, and suspected atomic bombs could wreak devastation on nearby Seoul.

But such an attack would be suicidal for the North Korean regime. Its outdated technology and limited resources are no match for South Korea and the U.S. And suicide is unlikely. As unpredictable as the North Koreans have proved to be over the past 60 years, the regime can be relied upon to seek self-preservation at all costs. More generally, while individuals may sacrifice themselves for a greater good, it is almost unheard of for nations to knowingly self-destruct.

The "go ballistic" option is useful to North Korea as a threat because they have power to execute it, but it is not useful as a strategy because it would not preserve the regime or further some greater objective. North Korea has made an economy of blackmail, representing itself as dangerous and holding the safety of Seoul hostage to its demands, but it will never make good on its threats unless there are no alternatives. The regime may launch a war if it were actually invaded, but it cannot afford to deliver "a 100- or 1,000-fold retaliation" to smaller provocations because it would not survive a full scale war. In the end, South Korea and United States hold the stronger hand.

The only impediment to the interception of North Korean vessels should be the responses of Russia and China. In order to be effective, the U.S. must do far more than intercept a single ship. It must cut North Korean's income from illegal weapons trade and make sure that it does not sell nuclear technology. Boarding the Kang Nam could provoke protests from Russia and China that would interfere with the long term goal of future searches. So the U.S. must either act with their tacit approval which it could secure behind the scenes, or else it needs to make sure to act against a vessel that is actually carrying prohibited cargo in order to spark outrage and receive support for further actions.

As for North Korea's bluster, we should avoid taking actions that would constitute a direct mortal threat to the regime, but otherwise, we can safely ignore it.