North Korea's Kim Jong-il has vexed regional neighbours for years with his pursuit of nuclear weapons and long-range missiles that may one day deliver them.
Known to his subjects simply as "Dear Leader", Kim, 64, is commander of the 1.2-million-man armed forces, the main advocate of a policy that gives the military a huge say in running the reclusive, impoverished state and, according to official media, an awe-inspiring master of military strategy.
Long groomed by his father, state founder Kim Il-sung, he gradually tightened his hold on power after the elder Kim died in 1994.
He declined to assume the title of president, instead designating his father "eternal president" and opting to rule as chairman of the National Defence Commission.
Some foreign North Korea watchers doubted whether he could stay on top for long given the power of the country's generals, but he has proved them wrong.
"His relation with the military is very strong because he has been focused on it since the start," said Michael Breen, author of "Kim Jong-il: North Korea's Dear Leader".
Breen said Kim has had to balance the interests of the military with those of advocates of a softer line, using diplomacy to wrest rewards in exchange for decreasing the country's military threat.
"This may have been a gesture to the hardliners," Breen said of Wednesday's tests of at least six missiles, which ratcheted up regional tensions and drew international condemnation.
Kim has been playing a cagey, defiant and sometimes deadly game with the international community for years.
He burst onto the world stage in 2000, hosting an unprecedented summit with then South Korean president Kim Dae-Jung. Landmark meetings followed with U.S. Secretary of State Madeleine Albright and Russian President Vladimir Putin, but the ray of sunshine out of the North soon came to an end.
In 2002, tensions rose on the peninsula after Washington said Pyongyang had admitted to pursuing a nuclear arms programme in violation of a 1994 agreement designed to freeze its atomic ambitions.
China then arranged and hosted talks aimed at resolving the crisis, having a reluctant North Korea sit down alongside South Korea, the United States, Japan and Russia. The talks have been stalled since November 2005.
According to North Korean propaganda, Kim is one of the greatest leaders in history.
After all, this is a man who pilots jet fighters -- even though he always travels by land for his infrequent trips abroad.
He has penned operas, produced movies and accomplished a feat unmatched in the annals of professional golf, shooting 11 holes-in-one on the first round he ever played.
This is also a man who intelligence experts say ordered the 1983 bombing in Myanmar that killed 17 senior South Korean officials and the destruction of a Korean Air jetliner in 1987 that killed 115.
In the cult of personality in North Korea, Kim, a short, tubby man with a pompadour and platform shoes, is king.
His legion of critics outside North Korea note that he spent great amounts on gigantic monuments and elaborate spectacles glorifying himself and his late father while, according to experts, at least 1 million North Koreans out of a population of 23 million starved to death in the mid-1990s.