April 5 - As Koreas face off, risk of accidental war grows

At the North Korean embassy in London, they are answering the phone but saying little. In fact, the world, well beyond Asia, is perplexed by the mysteries of the nuclear-capable state's bellicosity and many fear mutual ignorance could help turn words into acts of war.

Many foreign analysts offer reassurance. No one, they say, really wants war. Missile and nuclear tests, threats of possible atomic strikes on the United States and military drills on both sides of the divided Korean peninsula, reflect rather a youthful North Korean leader and newly elected South Korean government both finding their feet at home and testing their strengths.

Yet neither 30-year-old Kim Jong-un, who succeeded his late father just over a year ago, nor South Korea's President Park Geun-hye is seen having much room or appetite to back down. The risk of miscalculation or mistake sparking accidental conflict may be growing by the day - bringing with it the greatest risk in years of a regional nuclear exchange.

"We have had worrying times before, but this is bad," says Victor Cha, former director for Asian Affairs at the National Security Council under President George W. Bush. "The rhetoric is off the charts. We don't understand this new guy at all," added Cha, who is now a senior adviser at the Centre for Strategic and International Studies in Washington. "And if the North Koreans move to provoke the South, the South is going to retaliate in a way we haven't seen before."

This month's joint U.S.-South Korean military exercises have sparked outcry from the North and could make for the most dangerous weeks on the peninsula in more than two decades.

"There are number of ways this could go very wrong," says Ken Gause, chief North Korea specialist at the Center for Naval Analyses, a U.S. government-funded research institute that advises the U.S. military among others. "You have two new governments in North and South Korea that are still finding out where each other's red lines are."