A report published by South Korea's Defense Ministry on December 6 estimates that North Korea has further increased its focus on network and electronic warfare over the last year, doubling the size of its "cyber forces" to 6,000 soldiers. The report also warned that North Korea has made significant advances in its nuclear weapons technology and could now have the capability of threatening the mainland of the United States with a nuclear strike.

The report, the ministry's 2014 Defense White Paper, is a biennial review of South Korea's defense policy similar to the US Department of Defense's Quadrennial Review, intended to define the government's defense policy. Defense Ministry officials stated in the report that North Korea's efforts in cyber-warfare and other "asymmetric" capabilities are part of an effort to cause "physical and psychological paralysis inside South Korea such as causing troubles for military operations and national infrastructures."

The Defense Ministry report also claimed that North Korea had made advances in miniaturization of nuclear warheads, which

would allow them to be mounted more readily on intercontinental ballistic missiles. "The ability to miniaturize nuclear weapons seems to be at an early but significant level and is estimated as having the ability to threaten the US mainland through a long-range missile," a Defense Ministry spokesperson said in a summary of the report. The assessment is based on estimates of North Korea's production of highly enriched uranium.