There is a tendency for western media to treat Air Koryo, North Korea’s only "commercial" airline, as an opportunity for humor. The fact that it has been named the world’s worst airline by an industry group for four straight years plays a role in the company’s attractiveness as a butt for jokes, as do the propaganda films that play on its small fleet of Tupolev and Antonov jets (there is no volume control) and the mystery meat burgers served by its flight attendants.
But Air Koryo is no joke. It is an arm of the Kim family’s military-gangster complex, implicated in smuggling cash for Pyongyang’s slave labor enterprises, and has been implicated in weapons trafficking. Shutting off its routes to China and Russia should be a top priority for policymakers looking to respond to reckless North Korean behavior—like its belligerent launch of three missiles into the Sea of Japan during the G-20 summit this past weekend.
There is a case to be made that any cooperation with Air Koryo already constitutes a violation of resolutions passed by the U.N. Security Council, most importantly a measure from 2009 that establishes an embargo on "all arms and related materiel, as well as to financial transactions, technical training, advice, services or assistance related to the provision, manufacture, maintenance or use of such arms or materiel." How can this language apply to a commercial airline like Air Koryo? Because Air Koryo is not a commercial airline, but a branch of the North Korean military. As a U.N. report detailed in 2014:
Air Koryo and all airports or airfields within the Democratic People’s Republic of Korea are controlled by the Korean People’s Air Force through its Civil Aviation Bureau. Reportedly, all personnel are members of the air force and all in-country maintenance is conducted by Air Force engineering staff.
As military aircraft are surely "arms" or at least "related material," it follows that any "financial transaction" with Air Koryo ought to fall under the embargo—but countries with an interest in maintaining a relationship with the Kim family (like Russia and China) ignore this implication. But the military nature of Air Koryo is clear. A photograph obtained by the Washington Free Beacon shows the director general of Air Koryo, a man named Kang Ki Sop, wearing a military uniform and standing with Kim Jong Un and a group of North Korean military officials.
Kang is standing on the right. Other photographs of him are publicly available where he is wearing civilian clothes, as part of a North Korean effort to preserve the fiction that he is not a senior officer in the Korean People’s Air Force, but merely a civil aviation official.
Further photographic evidence of the military nature of Air Koryo was laid out in the 2014 U.N. report, which revealed that the North Korean government painted Air Koryo aircraft in military camouflage to use for a 2013 parade in Pyongyang. It then painted the aircraft back for commercial use, but evidence of the military paintjob was still visible when one of the same aircraft was photographed on the ground in Moscow.
Again, it is tempting to giggle at the poor quality of North Korean painting skills—but this business is deadly serious. Air Koryo represents one of a handful of vital lifelines for this largely isolated regime. Sources with knowledge of the matter say 
that Air Koryo aircraft were used to import "whole trunks" of cash salaries for thousands of North Koreans sent to work as effective slave labor in the Persian Gulf region, before the airline’s service to Kuwait City was cut off earlier this year. Air Koryo is attempting to restart its service to Kuwait, but Pakistan, where the North Koreans want to refuel their medium-range jets along the route, is currently refusing to participate. It’s not just cash: flights operated by Air Koryo or using paperwork provided by the company have been implicated in smuggling arms, including missile components, both in and out of the country.
For all these reasons, Air Koryo is under a tremendous amount of pressure: its flights to Kuwait have been stopped for now, along with routes to Bangkok and Kuala Lumpur. But it still operates semi-regular service to Beijing and Shenyang in China and Vladivostok in Russia. If only for reasons of safety, even the Chinese appear to be tiring of North Korea’s antics. This July, an Air Koryo flight from Pyongyang to Beijing caught fire in midair, forcing the aircraft to land in Shenyang instead. China’s government issued a stern safety warning to its restive neighbor, and said it would be "limiting" cooperation with the airline.
If even the Chinese are wavering in their support for Air Koryo’s continued operations, then this lifeline for the Kim regime is an excellent target for international pressure. Any new U.N. resolutions responding to North Korea’s aggressive behavior ought to make explicit the fact that Air Koryo is a branch of the North Korean military, and ought to forbid any cooperation with it whatsoever. A resolution passed in March of this year already requires an increased level of scrutiny and inspection for all North Korean aircraft, including flights operated by Air Koryo, but this isn’t enough. This sham of an "airline" should no longer be permitted to fly on any international routes.