North Korea endured international humiliation with five failed launches in about two months before it finally pulled off what appears to be a successful test of a powerful new midrange missile. Scientists managed to satisfy a direct order from an impatient strongman looking for a credible military backup to his repeated threats to strike his enemies in all corners of Asia.

The latest development came Wednesday, with back-to-back launches of what Seoul, Tokyo and Washington believe are Musudan missiles, the second of which appeared to succeed.

The North's remarkable commitment to quickly launching the missiles, despite the failures, flies in the face of past practices, when scientists usually took their time after a bad launch to figure out what went wrong and make adjustments.

But leader Kim Jong Un may have turned up the pressure on his scientists and military with his very public order in March to push ahead with more nuclear and missile tests. Such a burden from a boss who has shown a willingness to use violence against his underlings — ordering even his own uncle's execution — may toss normal scientific patience out the window.

Kim leads a small, impoverished, authoritarian country that sees itself beset with much larger enemies intent on its destruction. To protect his third-generation family dynasty, he may calculate that he needs to make North Korea appear too dangerous for Washington to try to topple him.

He may have been willing to weather outside mockery for progress on a missile whose development marks a big step toward North Korea's goal of a comprehensive nuclear and missile program that can deliver atomic bombs and missile strikes to U.S. targets around the world, including, eventually, the U.S. mainland.

Five of the North's six suspected Musudan launches failed, many exploding in midair or crashing. The sixth on Wednesday flew about 1,000 kilometers (620 miles) high and a distance of about 400 kilometers (245 miles), South Korean and Japanese officials said. That indicated a success for some observers.

The North's repeated tests of the Musudan worry Washington because the missile's potential 3,500-kilometer (2,180-mile) range puts a lot of Asia and the Pacific, including U.S. military bases, within reach.

Some analysts have been thrown by the speed with which North Korea moved on the suspected Musudan tests.

The first launch came on April 15, and was linked by outsiders both to Kim's March order and to the birthday anniversary that day of North Korea founder Kim Il Sung, Kim Jong Un's grandfather. Less than two weeks later, North Korea conducted two more launches. The next came June 1, and then came Wednesday's double firing.

"Repeating a failed test again and again with no more than a month for analysis and troubleshooting will almost guarantee repeated failure," according to aerospace engineer John Schilling, writing earlier this month, after the fourth test.

North Korea is extremely sensitive to outside criticism. Pyongyang, for instance, said Monday it won't negotiate to release arrested American citizens if a former U.S. detainee, Kenneth Bae, doesn't stop using what it called slanderous language about the North.

But even more important for the leadership is the support of the elite in Pyongyang, the North's capital.

North Korea said nothing in any of its state-run media about the launches, meaning most people in insular North Korea probably knew nothing about the duds.

For Kim Jong Un, a final, apparently successful launch of a missile that could be a real threat to his enemies may ease the pain of all the previous failures, especially since most of his people were unaware of them.

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Foster Klug, AP's bureau chief in Seoul, has covered North and South Korea for more than a decade. Follow him on twitter at www.twitter.com/apklug