The UN Security Council vowed Sunday to impose new sanctions on North Korea after the militant nation launched a long-range rocket.

The launch defied warnings from the international community as well as current sanctions. While North Korea says it launched an observation satellite, the UN is among those calling it a covert test of the technology needed for a missile that could hit the U.S.

Here's a primer on the must-know facts on North Korea in light of this launch and the nuclear test it conducted on Jan. 6.

Why is North Korea building up its arsenal?

Andre Schmid, an associate professor at the University of Toronto's Department of East Asian Studies, says we must remember that North Korea still considers itself at war with South Korea and the United States.

"North Korea was very aware that the United States had nuclear weapons stationed in South Korea until at least the 1980s, and so their research on nuclear weapons goes back a long time."

He says North Korea sees building a nuclear and missile arsenal very much in terms of self-defence. "People forget that longer history, which is often driving North Korean motivation, that memory of the possibility that nuclear weapons might have been used against them."

Additionally, being able to produce nuclear weapons is a matter of national pride. "If you think of it in terms of scientific advancement, it's something that they can celebrate inside their country. In a time of so many difficulties, it comes across as sort of this nationalistic accomplishment."

Rodger Baker, vice-president of Asia Pacific analysis for geopolitical intelligence firm Stratfor, adds that North Korea is also trying to develop "a recognized nuclear deterrent that can influence decision-making in the United States on North Korean policy."

Why did North Korea launch this rocket now?

It might just be because this is when it was completed. Baker says that "the timing of [North Korea's] tests these days often has more to do with the status of their technology than with a specific political statement."

However, he notes that the upcoming Workers' Party congress, slated for May, likely also affected the timing of the launch. The first congress since 1980, if all goes well, will solidify Kim Jong-un's leadership, making now the time for shows of power.

Should the world be worried?

Schmid says there's no definite answer.

"What's pretty clear is that they now have a long history of experimenting with both nuclear weapons and ballistic missiles. And so any estimate of this threat is going to depend upon your conclusions about how quickly they're developing these technologies. And the truth is, we just don't know."

Baker doesn't think North Korea poses much direct risk, because "it's a regime that understands that any truly aggressive action ultimately will lead to its own destruction."

Even if North Korea could launch a missile with its current technology, it's debatable how effective it would be.

"It takes several days for this particular missile system to be set up and fuelled up and ready to launch," Baker says. "There's really only a few sites where it can be launched from, it's heavily watched, so they can't really use it."

He says the real threat created by North Korea is proliferation. Its actions have South Korea and Japan tentatively discussing their potential need for nuclear weapons.

What is the international community doing?

Beginning in 2006, the United Nations has repeatedly passed sanctions against North Korea. These sanctions have included asset freezes, travel bans, arms embargoes and restrictions on luxury items. They're intended to make life more unpleasant for North Korea's ruling class, creating political friction.

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North Korean leader Kim Jong-un waves in this undated photo released by North Korea's Korean Central News Agency. (Reuters)

However, Schmid says "there's a lot of debate about how strong those sanctions are, partly because there are a lot of loopholes."

For instance, under the UN rules, each country can decide what qualifies as "luxury goods." While the United States has a long, public list of goods that can't be traded with North Korea, China has very lax restrictions. Schmid says a $6-million yacht reached North Korea via China, and Mercedes Benzes still enter the country.

It remains to be seen how tightly the UN's new sanctions will be enforced.

South Korea and the U.S. have agreed to begin discussion about deploying a missile defence system called THAAD in South Korea.

What can the world do?

"There's the question of do you want to go after some of the banks that North Korea's involved in [with sanctions]" says Schmid. "That's the big question that's being faced right now, and the difficulty of course is that many of those banks do a lot of business with China."

Baker doesn't think further sanctions are the answer. "Isolation clearly is not working and the North Koreans are trying to emphasize that. So to shame them or make them sit on the stairs or something is doing very little to stop them."

He acknowledges that it's a difficult situation with no easy answers, but he doesn't think the U.S. tactic of refusing to engage is the solution.

"I wouldn't argue that dialogue and engagement will solve the problem, but I would argue that a lack of dialogue and a lack of engagement may hamper any move toward a solution."

Why can't we just bomb them?

Schmid says that even if you were to destroy North Korea's nuclear facilities, you need to remember how close you are to major Asian cities like Seoul, Beijing and Tokyo. "The fear that radiation would spread from any type of attack on its facilities is pretty severe."

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People watch a TV news report of a rocket launch in North Korea. (Ahn Young-joon/Associated Press)

"You also want to remember that North Korea has thousands of artillery pieces that are pointing at Seoul, so they can use even conventional methods," he says.

Additionally, the U.S. has tens of thousands of troops just south of the demilitarized zone who could be potentially put in harm's way.

"I think the fragility of the security situation is such that everybody's worried [about taking] a wrong step," he adds.

Where does the world draw the line?

"Well, the line used to be drawn at they shouldn't be allowed to test a nuclear weapon. That line has obviously been crossed multiple times now," says Baker. "The idea of red lines seems to have been left in the dust in the North Korean situation."

He thinks that if the country started selling nuclear weapons or testing them over the ocean, "people may be upset, but by that point North Korea would have clearly demonstrated a capability and therefore, what are you going to do to constrain them?"

Where does this leave China?

The Asian superpower is North Korea's strongest ally. In 2014, 90 per cent of North Korea's international trade was with China.

Following the rocket launch, a Chinese Foreign Ministry spokeswoman, Hua Chunying, advised other countries to act with calm and discretion and not escalate the issue.

Schmid says recent statements from Chinese and American officials imply that they blame each other's foreign policy for the rocket launch. Whereas the United States refuses to engage with North Korea, China believes in peacefully negotiating with Pyongyang.

"They're both pointing fingers at each other, using this as evidence of the failure of the other half's policy."

"China's going to try still to keep this … within the Security Council, rather than unilateral action," says Baker.

He points out that China summoned the South Korean ambassador to complain about South Korea discussing the possibility of a missile defence system.

"That suggests that we're not going to see a lot of dramatic action from the Chinese on this."