As I reported recently, in 2016, North Korea tested 26 missiles; 16 of those tests were successful and 10 failed, according to a database maintained by the Nuclear Threat Initiative. So far this year, there have been 19 tests—counting Thursday’s: 13 successes, five failures, and one unknown. Not only is North Korea showing its increasing ability to successfully test missiles—62 percent success rate in 2016 vs 68 percent so far this year, including Thursday’s—but it is also well on its way to exceeding the number of tests it carried out last year. This suggests that the North isn’t really worried about its supply of missiles; in other words, it’s now making its own.

And despite the frequency of tests, overflying Japan is an escalation. As my colleagues Yasmeen Serhan and Kathy Gilsinan noted when a North Korean missile overflew Japan in late August—the first time such an event had occurred in eight years—the North’s technical ability to do so had been known before. But the message then, as now, may have been more political than technical. They wrote:

James Acton, the co-director of the nuclear policy program at the Carnegie Endowment for International Peace [said]: “I think you have to look at this test more than anything else as a signal to the United States.” ... Having warned North Korea in unusually bellicose terms not to threaten America earlier this month, President Donald Trump at a recent rally noted that he thought Kim Jong Un was beginning to respect the United States, given what seemed to be a pause in North Korea’s missile testing. That apparent pause ended last Friday as the United States and South Korea engaged in annual joint military exercises that the North has long viewed as a provocation. (North Korea has tested missiles during such exercises in the past.)

Still, the missile tested Thursday, like the one tested in late August, followed a flight path over northern Japan, and away from the American territory of Guam, which North Korea’s Kim Jong Un had threatened earlier in the summer. The provocation now as then may be calibrated to avoid direct confrontation with the United States, though the U.S. has maintained it hasn’t ruled out any option for dealing with North Korea.

North Korea’s nuclear and missile technology is by no means state of the art. For decades, it relied on technology and parts from the Soviet Union, Russia, China, Iran, and Pakistan. So the technology is tried and tested, and the North, in the face of international sanctions, now seems to be able to make the parts needed for its ambitious military programs. (Nor is North Korea’s economy as hamstrung as many in the West believe, according to Mitsuhiro Mimura, a Japanese economist, who has visited the North 45 times since 1996. In an interview with 38 North, the North Korea-focused website, Mimura called the North the “poorest advanced economy in the world—but what’s important to understand is that, while it may be poor, it is still an advanced economy.”)