Writing for 38north.org, Jenny Jun speculated that Beijing might have "experienced a classic mismatch between means and ends when efforts to maintain the status quo by propping up the internal regime ended up propping up the North's nuclear program as well."
What standard of living do ordinary North Koreans have?
In 2011, UNICEF estimated that about a quarter of North Korea's population -- or six million people -- did not have enough to eat. Nearly a million of those were children under the age of five, it said. UNICEF said food was rationed in North Korea and that the country was "susceptible to food crises because of political and economic isolation, and climate change."
The World Food Programme says North Korea continues "to face regular, significant food shortages," with one in every three children chronically malnourished or too short for their age.
The United States suspended shipments of food aid to North Korea in 2009 after the North started rejecting shipments amid tensions over Pyongyang's nuclear program and concerns that the supplies were not reaching those most in need.
In March 2012, Pyongyang agreed to halt portions of its nuclear and missile programs and accept the return of nuclear inspectors in exchange for 240,000 metric tons of U.S. food aid.
However, later the same month North Korea's announcement of another rocket test ended the deal.
Hoare said the standard of living in Pyongyang differed from other parts of the country. "Pyongyang is the elite. A lot of people do have money -- the restaurants are used by Koreans, officials and others. Elsewhere, senior officials will have access to funds.
"Most people live a pretty hand-to-mouth existence in the North apart from the elite."
The diet of North Koreans was a "much more reduced one than that in the South," he said. "Most people live on grains and vegetables with meat and fish very, very, rare in their diet. Even in Pyongyang, people aren't living that high on the hog," he said, although the elite and foreigners were protected.
Why is North Korea's economy in such bad shape?
The official economy was based around heavy industry on North Korea's east coast and until at least the mid-1970s, North Korea was one of the two main industrial nations in Asia, alongside Japan, Hoare said. While not an official member, North Korea had also benefited from the Soviet-led Council for Mutual Economic Assistance -- an economic union between Soviet states referred to as Comecon.
However, the collapse of the Soviet Union and a series of natural disasters saw its industrial sector enter a steep decline in the 1980s, which further intensified in the 1990s, leaving the economy "pretty decrepit," he said. The country also had an oil shortage. "It used to get its oil from the Soviet Union, it doesn't anymore," Hoare said. Agriculture had been on a "downward spiral" since the 1980s, with an overdependence on fertilizers. "The land is worn out, people are worn out, equipment is worn out."
But it's difficult to get reliable information on North Korea's economy. Hoare said Pyongyang had not published any statistics on its economy since the early 1960s. "This is all a very murky and difficult area. It's not clear, it is opaque and it's hard to get very precise figures and an exact picture. That's the nature of the animal," he said.
The country also had electricity shortages, he said, which was one of Pyongyang's arguments for developing nuclear power.
Since Pyongyang's first nuclear test in 2006, the U.N. Security Council has also targeted North Korea with sanctions over its nuclear and ballistic missile programs.
It has frozen economic assets controlled by entities engaged in or providing support for North Korea's nuclear and ballistic missile-related programs.
New sanctions introduced in March blocked the sale of luxury goods -- such as yachts and certain high-end jewelry -- to North Korea.
Don't the sanctions affect ordinary North Koreans?
U.S. Ambassador to the United Nations Susan Rice said the block on luxury goods would mean "North Korea's ruling elite, who have been living large while impoverishing their people, will pay a direct price" for the country's nuclear activities.
Jang said a body known as "Office 38" generated money for North Korea's ruling party and the infrastructure of the elite and had been seen as Kim Jong Il's personal fund when he was alive. It was foreign currency based, he said.
He said there was also a "people's economy" mainly based on the black market since North Korea's won currency had lost value.
This market economy had emerged "partly as a coping mechanism as a result of the famine - since the 1990s," Hoare said. He broke the economies down into the official economy, the people's economy, a military economy and an economy "to keep the leadership in the style to which it is accustomed."
What about the arms trade?
In its March 2013 resolution following North Korea's February nuclear test, the U.N. Security Council referred to the Korea Mining Development Trading Corporation (KOMID), as North Korea's "primary arms dealer and main exporter of goods and equipment related to ballistic missiles and conventional weapons."