On December 11, according to Barbara Starr of Jane's Defence Weekly (p. 10), former CIA Director Robert Gates told the United States Senate Intelligence Committee that North Korea is having problems developing its Taepodong class of ballistic missiles. He said that research and development were needed for a completely new propulsion system, plus improved guidance. Gates said that economic, technical, and manufacturing problems in North Korea's infrastructure make the development of this new class of missiles unlikely.