Hyonhee Shin, Josh Smith

SEOUL (Reuters.) – South Korea’s military claims that North Korea launched its largest ever missile test using an older and smaller intercontinental ballistic weapon. This was partly to avoid domestic repercussions.

According to a defense ministry official, the South Korean and American officials concluded that the March 24 launch appeared to be a Hwasong-15 ICBM. This is due in part because the subject matter is sensitive.

Washington hasn’t yet made public a decision, but John Kirby (NYSE; Pentagon) stated Tuesday to reporters that the Pentagon was continuing its analysis of the test.

North Korea tested the Hwasong-15 first in November 2017, and then imposed a moratorium against ICBM testing, which ended last week.

After the launch of the missile, open-source analysts noticed discrepancies between video and photographs. They said that shadows and weather suggested that it had been from an earlier test.

“The choice of the Hwasong-15, which is more reliable with the successful test in 2017, could be intended to block rumours and ensure regime stability by delivering a message of success within the shortest time possible, after residents of Pyongyang witnessed the failure of the March 16 liftoff,” the defence ministry said in a report provided to parliament and obtained by Reuters.

According to the report, this test may have also been intended to boost its military strength and increase bargaining power in the face of South Korea, America, and other countries.

According to U.S. officials, South Korean officials said the Hwasong-17 system was tested on March 27 and 5, possibly in preparation for a full range launch. North Korea has never admitted the launch of March 16, nor its failure reported.

According to Ha Tae-keung (South Korean lawmaker), debris from the failed test fell on Pyongyang.

That failure prompted North Korea to tell a “big lie” and say the March 24 Hwasong-15 launch was a Hwasong-17 to avoid negative domestic public opinion, Ha said.

State media reports that Thursday’s missile flew for 67.5 minute to an altitude of 6,248.5km (3,905 miles), with a range between 1,090 km (61 miles). These numbers match data from Japan and South Korea. They are also higher and more consistent with the initial Hwasong-15 missile test that flew for 53 mins at an altitude of approximately 4,475km and a range of 950km.

According to the report, Thursday’s missile characteristics such as ascending acceleration, combustion and stage separation times, are similar to Hwasong-15’s. The flight also flew further than expected and reached higher altitudes.

South Korean officials suggested that North Korea might have launched a Hwasong-15 without any significant payload or modified it.

According to analysts, the explosion that occurred on March 16th may have been due to a problem with the engines. According to the ministry, the Hwasong-17 required a cluster of four Paektusan engines, compared with two for the Hwasong-15. It also noted that there was only eight days between launch and the explosion.

Vann Van Diepen (an ex-official U.S. government employee involved in nonproliferation and weapons of mass destruction) stated that “March 16 was a Hwasong-17 fail and March 24 was Hwasong-15.”

The Hwasong-15’s reliability would be confirmed by a second, successful testing, however, the impact of the reduced payload would only have been limited, he stated.