Shortly after North Korea launched the Hwasong-12 in May, the scientists who developed the intermediate-range ballistic missile were honored on the streets of Pyongyang as national heroes.

“The buses carrying them went through the streets of the capital full of flowers of welcome,” KCNA, the state-run news agency, reported at the time. “Citizens warmly congratulated them, waving flags of [North Korea], red flags and bouquets.” Among those offering his congratulations was Kim Jong Un. KCNA reported that the 33-year-old North Korean leader “hugged officials in the field of rocket research, saying that they worked hard to achieve a great thing.”

Scenes like those will probably be repeated over and over again if the last few months are any indication. So far in 2017, the North has carried out a dozen successful missile tests, and is well on its way to surpassing last year’s 14 successful launches. Two of this year’s tests were of intercontinental ballistic missiles (ICBMs) that are capable of reaching the United States. In this time, North Korea has also been assessed as possessing a miniaturized nuclear warhead that can be fitted onto an ICBM. Last week it stunned the world by testing what it called a hydrogen bomb, far more powerful than anything the U.S. dropped on Hiroshima or Nagasaki. The accomplishments are all the more impressive given that North Korea is one of the most heavily sanctioned countries in the world; until recently was one of its most reclusive; and has a leader who can seem almost cartoonish until he shocks the world with yet another missile or nuclear test.

The place North Korea’s missile and nuclear program holds in the national psyche can be understood in part through the esteem in which scientists are held in the country. There are many high-profile residential construction projects devoted to scientists and their families. State-run media report on the honors they receive after nuclear tests and missile and space launches. They get parades like the one in Pyongyang in May.

“I’d say it’s the most prestigious job in the country right now,” Joshua Pollack, a senior research associate at the Middlebury Institute of International Studies at Monterey, told me. “It used to be that they emphasized the importance of the military in their politics. Now they’ve begun de-emphasizing that and they’ve begun to emphasize the role of scientists in society both for advancing their economy and, even more than that, for advancing their nuclear weapons and missile technology.”

Although scientists are honored and rewarded, they also remain under pressure to produce increasingly better results. There’s a real possibility, said Vipin Narang, an associate professor of political science at MIT, that Kim, like his father Kim Jong Il, “threatened these scientists with their lives if they don’t make progress. That can be a very powerful motivator.”

Whatever the motivation, the results are impressive. Consider this: In 2016, North Korea tested 26 missiles; 16 were successful and 10 failed, according to a database maintained by the Nuclear Threat Initiative. That’s an approximately 62 percent success rate. There have been 18 tests in all so far this year: 12 successes, five failures, and one unknown. That’s a 67 percent success rate. Those figures underscore what Pollack said about North Korea being “determined to break through.” Another thing to consider—the number of tests so far this year.

“The fact that they are willing to test missiles so frequently suggests they are not really worried about supply,” Narang said. “And if you didn’t have the ability to produce so many missiles, then you might be a little more reluctant to test.”

There’s evidence to suggest that North Korea is, in fact, accelerating its push toward the domestic manufacturing of parts needed for its missile and nuclear programs, turning slowly away from the international black market on which it had traditionally relied. Andrea Berger,  a senior research associate at the Middlebury Institute of International Studies, said in an interview last week that North Korea has increasingly indigenized manufacturing. “Some of the goods they needed to once procure from overseas, they are now able to make domestically, which creates a local supply chain for, for example, missiles,” she told me.

That’s not to say that North Korea’s missile and nuclear technology is state-of-the-art. Many of the designs date back to the Cold War, when the North received nuclear technology from the Soviet Union. Over the years, it acquired weapons technology from China, Iran, Pakistan, and others, and through what can only be described as perseverance cobbled together successful programs.

“That’s where I think it's really impressive—the innovation by necessity that they’ve had,” Narang said. “It’s a country under sanctions. It’s a country under threat.” The technology, training, and assistance North Korea has received may be old, but “when you have a cadre of scientists and engineers that are familiar with it … it’s not surprising that they’ve gotten better at it.”

Pollack pointed out that while North Korea’s technology isn’t “cutting edge, … it’s commensurate with their capabilities and the level of effort they’ve put into it.” He said the country’s defense industry was robust; its scientific literature and industrial facilities expanding. Photographs of production facilities and production equipment, he said, display equipment that is “increasingly pretty sophisticated.” And, he pointed out, as advanced manufacturing technology becomes more easily available worldwide, “this is only getting easier to do over time.”

The experts I spoke to said they weren’t surprised that North Korea had made the kinds of advances it had, even though they were surprised at the pace at which North Korea had progressed. Daryl Kimball,  the executive director of the Arms Control Association, told me, it was a “mystery” how Pyongyang had made gains so rapid that they were now viewed as a threat to the United States. Pollack said North Korea has “been systematically underrated for years.” Narang told me the pace of North Korea’s development surpasses similar programs in India, Pakistan, South Africa, Israel, and even France—and showcases the country’s metallurgical and engineering technology.  

“It’s pretty impressive,” he said. “And it suggests they’ve figured out how to do a lot of things, and they are willing to have higher tolerances for failure and for less reliability.” That, ultimately, might be North Korea’s biggest advantage in the current standoff with the U.S. and its allies.

Narang pointed out that the probability that North Korea is able to deliver a nuclear warhead over San Francisco, or Chicago, or a city on the U.S. East Coast, is not 100 percent—because its technology is not yet that accurate. “But to deter the United States or really induce risk, what percentage is necessary before you cause Washington to have some pause: Is 5 percent acceptable? Are you willing to lose 5,000 to 50,000 Americans, on average? Probably not, right?

“And if you’re truly talking about a thermonuclear warhead, you could be talking about … millions of casualties. We need to get beyond this notion that it has to be perfect, and it has to be accurate. The larger the warhead, the less accurate it needs to be.”