According to Wikipedia, North Korea have around 35 nuclear missiles with range up to 3000 km, see link here
https://en.wikipedia.org/wiki/North_Korea#Military. I think North Korea manufacturing quality is much lower than Chinese, so nuclear missiles bad quality can lead to wrong direction during test flights. What will do US warships in the region, if North Korea missile go in wrong direction because of manufacturing mistake ?
North Korean missile launch that failed shortly after it was fired may have been thwarted by cyber attacks from the US.
The medium-range missile exploded seconds after it was launched on Sunday from a site near the port city of Sinpo, as Mike Pence, the US vice president, arrived in Seoul for talks with the South Korean government over how to deal with Pyongyang's belligerence.
"It could have failed because the system is not competent enough to make it work, but there is a very strong belief that the US - through cyber methods - has been successful on several occasions in interrupting these sorts of tests and making them fail," the former Conservative foreign secretary Sir Malcolm Rifkind told the BBC on Sunday.
In 2014, former US president Barack Obama ordered that efforts be stepped up to counter North Korea's missile capabilities with cyber attacks and electronic warfare. North Korea has seen a significant increase in failed launches in the years since, though there has been no official claim of the programme's success.
