For decades, because North Korea has defied the international community's demand that it give up its nuclear ambitions, it has become the target of escalating sanctions — the latest of which, says Stephan Haggard of the Peterson Institute for International Economics, are "perhaps the most significant ... with respect to any country ever."

Expand chart Data: The Observatory of Economic Complexity; Chart: Chris Canipe / Axios

Why it matters: As the visualization above shows, North Korea is critically reliant on trade with China. That's why experts hope that the latest round of sanctions, including a U.S. threat to block any company or bank that does business with North Korea from using the U.S. financial system, will kickstart negotiations.

According to the United Nations, total trade to and from North Korea was $6.3 billion in 2015. The biggest imports were oil and high-tech products like computers and video displays. North Korea's biggest export were coal and textiles. China dominates this type of trade with North Korea, but it has already cut off coal imports.

As of Jan. 1, China said it will halt natural gas exports to the country, and limit oil shipments to 2 million barrels a day, although it is not clear whether that is an actual reduction in oil sales.

Guest workers: What's more difficult to count is how much North Korea spends and receives for services. This includes remittances from North Korean laborers working in China. There are no public numbers on how many North Koreans are working in China, but estimates range from 19,000 to 100,000. Much of what these workers are paid ends up back in the pockets of the Kim regime, providing much needed hard currency, and facilitating imports.