If N. Korea Keeps at It, Nuke Could Reach US: Report Pyongyang is critical security challenge to US: Pentagon By Ruth Brown, Newser Staff Posted May 3, 2013 9:04 AM CDT 21 comments Comments In this file photo taken Sunday, April 15, 2012, what appears to be a new missile is carried during a mass military parade at the Kim Il Sung Square in Pyongyang, North Korea. (AP Photo/Ng Han Guan, File) (Newser) – The Pentagon's annual report card on North Korea's military capabilities gives the dictatorship an A for effort: It says that if Pyongyang continues to apply its very limited resources to nuclear tests and improving technology, its Taepodong-2 missile could eventually reach US shores, Reuters reports. "Advances in ballistic-missile delivery systems, coupled with developments in nuclear technology ... are in line with North Korea's stated objective of being able to strike the US homeland," says the report. The Pentagon says it expects leader Kim Jong Un to carry on his father's agenda of "reunifying" the two Koreas by increasing its military capabilities against South Korea, CNN reports. Although the military power of South Korea and the United States provides a strong deterrent from an outright attack, just how rational Pyonyang would be in determining the risk of counterattack is not clear. "Although North Korea is unlikely to attack on a scale that it assesses would risk the survival of its government ... we do not know how North Korea calculates this threshold of behavior," says the report. "North Korea's use of small-scale and provocative acts leaves much room for miscalculation that could spiral into a larger conflict."