The new agreement on strategic partnership signed by Russian President Vladimir Putin with his North Korean counterpart Kim Jong Un could potentially cause friction between North Korea and China, which has long been the country’s main ally, states Air Force General C.Q. Brown, chairman of the Joint Chiefs of Staff. “We’ve got someone else who’s kind of nudging in now, so that may drive a little bit more friction between (China) and Russia. So it’ll be interesting to see how these three countries — how this plays out,” the general told journalists during a foreign meeting. Brown acknowledged t…