North Korean missile advances expose Japan in two-decade arms race: sources

Members of the Japan Self-Defence Forces stand guard near Patriot Advanced Capability-3 (PAC-3) land-to-air missiles, deployed at the Defense Ministry in Tokyo, Japan, December 7, 2012. REUTERS/Issei Kato/File Photo

TOKYO (Reuters) - Successful rocket tests have propelled North Korea ahead in a two-decade long arms race with Japan, leaving Tokyo unsure it could fend off a missile strike by the Pyongyang regime without U.S. help, military sources told Reuters.

Under young leader Kim Jong Un, North Korea has test fired 21 ballistic missiles since the start of the year, an unprecedented burst of activity that has rattled its neighbours and the international community.