South Korea and the US have begun joint military naval drills, despite North Korea's threats of possible retaliation. Pyongyang called the action a silent declaration of war, though its neighbour states the 12-day military games are purely defensive.RT talks to Ruediger Frank who is an expert on North Korea and East Asia at Vienna University.<br /><br />RT on Facebook: http://www.facebook.com/RTnews<br />RT on Twitter: http://twitter.com/RT_com
