The U.N. Security Council issued the latest sanctions because Pyongyang violated earlier resolutions barring it from conducting nuclear or missile tests. The council passed those measures because it considers North Korea's nuclear testing a threat to international peace and stability.
North Korea dismisses that as a double standard, and claims the right to build nuclear weapons as a defense against the United States, which it blames for leading the push for sanctions.
Pyongyang said before the U.N. vote that it would scrap the armistice that ended the Korean War, and after the vote issued a statement saying it was canceling a hotline and a nonaggression pact with rival South Korea.
The U.N. tries to tailor its sanctions to punish the leadership, not average North Koreans. But it's an imperfect exercise.
The latest sanctions will squeeze North Korea's already meager exports and imports, which will in turn cause pain for citizens, said Cho Bong-hyun, a research fellow at the IBK Economic Research Institute in Seoul.
"North Korea's economy faces so many difficulties already, and it can get even worse (because of the sanctions)," Cho said.
A glimpse of North Korean thinking on sanctions can be seen in a wave of recent warlike threats from North Korea. Fierce language associated with the specter of yet more sanctions leveled at the North by Washington and its allies feeds into an us-against-the-world mentality.
It is meant to "solidify Kim Jong Un's leadership by creating a state of quasi-war and tension," said Koh Yu-hwan, a North Korea expert at Seoul's Dongguk University.
Immediately before the Security Council vote, a spokesman for Pyongyang's Foreign Ministry said the North will exercise its right for "a pre-emptive nuclear attack to destroy the strongholds of the aggressors" because of the U.S.-led push for sanctions and U.S.-South Korean joint military drills.
The primary intended audience for such rhetoric is often not outsiders but North Koreans.
When a crisis looms, soldiers, officials and propaganda writers vie with each other to show their extreme loyalty to, and to win promotion and praise from, the ruling Kim family.
Analyst Baek Seung-joo, of the South Korean state-run Korea Institute for Defense Analyses, said it's "like a loyalty competition."
One caveat to the sanctions dilemma is China, which is North Korea's economic lifeline, providing almost all the country's oil and generous amounts of food aid.
Pyongyang's dependency on Beijing has grown as sanctions have piled up. Chinese products made up only about 43 percent of North Korean imports in 2006, compared to more than 95 percent in 2012, according to data from the International Trade Centre. The group, a joint agency of the U.N. and the World Trade Organization, said more than $3.5 billion in Chinese exports reached North Korea last year.
Beijing's backing for the new measures signals its growing frustration with its neighbor and ally.
"In the past, we opened our eyes and closed our eyes as need be. Now we're not closing our eyes anymore," said Cui Yingjiu, a retired professor from Peking University in China and a former classmate of Kim Jong Il.
But Chinese leaders have been wary of putting too much pressure on Pyongyang for fear that the Kim government would collapse, sending North Koreans streaming across the border and potentially leading to the loss of a buffer against a U.S.-allied South Korea.
If China changes course and rigorously enforces the U.N. resolution, "it could seriously disrupt, if not end, North Korea's proliferation activities. Unfortunately, if past behavior is any guide, this is unlikely to happen," Marcus Noland, a North Korean watcher at the Peterson Institute for International Economics in Washington, said in an institute blog post.
Guttenfelder reported from Pyongyang, North Korea. AP writers Hyung-jin Kim, Sam Kim and Youkyung Lee in Seoul, Jean H. Lee in Pyongyang and Charles Hutzler in Beijing contributed to this report.