- That the world's mightiest military feels the need to flash its billion-dollar weaponry only shows how frustrated the U.S. is by North Korea.
- Kim has had extraordinary success in his first year, and that may have gone to his head.
- Kim may also believe that testing South Korea's new president is a good bet.
Can a B-2 stealth bomber prevent war in Korea? Last week's U.S. flyby over the Korean peninsula suggests that the Obama administration is hoping so. That the world's mightiest military feels the need to flash its billion-dollar weaponry only shows how frustrated the U.S. is by North Korea. Unfortunately, U.S. posturing will mean little if an increasingly bellicose Pyongyang has already taken Washington's measure and found it wanting.
Raise the prospect of war and jaded Korea watchers will say that we've seen this all before. In the past, the North has cut off communications and announced its abrogation of the 1953 Korean armistice—same as Pyongyang did last week—without calamitous effect. The Kim family has made an art of keeping Washington and Seoul off balance and then blackmailing them into coming back to the negotiating table.
Yet, as they say, this time may really be different. For starters, Kim Jong Un may not be his daddy's boy. He has had extraordinary success in his first year, and that may have gone to his head. In addition to presiding over a third successful nuclear test, he has successfully launched a long-range ballistic missile and put a satellite into orbit. Young Kim has of course piggybacked off the efforts of his forebears, but the triumphs have nonetheless come on his watch.
Kim may not have the same patience for the long game as his father. He may believe that the stars favor him and that he can push farther and faster than usual. That may mean a set of attacks on South Korea similar to those his father undertook in 2010, when Pyongyang sank a South Korean naval vessel and shelled the border island of Yeonpyeong. While Kim Jong Il stepped back after these provocations, the younger Kim may believe that his country is now stronger and more able to resist pressure from Seoul or Washington.
Kim may also believe that testing South Korea's new president is a good bet. If he can successfully cow Park Geun-hye today, he would have a complaisant Seoul to deal with for the next six years. That may lead to more concessions such as monetary support or a loosening of Seoul's U.S. alliance.
What Kim certainly does not want is a South Korea confident that it can not only defend itself with U.S. support, but also actively deter the North from its usual aggression. He could figure that the way to shatter such confidence is to hit hard early, make even more extravagant threats and send a clear warning that Pyongyang will hold the cards of peace or war.
Finally, the new Kim regime has already faced down and bested the Obama Administration twice. It brazenly broke an agreement to not launch missiles, doing so twice since 2012, and set off another nuclear test this past February. The response from the Obama Administration will likely be numbered in new United Nations resolutions and little else. They will be as useless as the previous responses, not least due to continued opposition from China.
In short, Kim has seen his enemy and the sight holds no fear for him. Thus his willingness to be even more obstreperous than usual.
All that confidence would likely not matter much should Kim overshoot and actually launch a war or an extended attack on South Korea. In that case, it is hard to imagine Seoul holding its fire, or the U.S. forsaking its ally. To that point, in addition to the B-2 flyover last week, the U.S. sent F-22 fighter jets to Korea over the weekend. Last week Seoul and Washington also signed a new pact agreeing to a military response that covers even limited attacks of the type seen two years ago.
Under this new agreement, Seoul would take the lead in any military response, with U.S. forces acting in a supporting capacity. That tracks with statements by former president Lee Myung-bak, who promised swift and overwhelming retaliation for any further attack by the North.
Yet given numerous, though unsubstantiated, reports that Washington restrained Seoul from a response after North Korea's island-shelling in 2010, the new pact may not have the impact the allies want. It all depends on the strength of action South intends to take, and whether Washington will back up Seoul.
Kim knows that he and his father have escaped serious repercussions from their repeated aggression. That appears to be emboldening the young leader to a degree that dramatically increases the risk of miscalculation, and perhaps makes backing down more fraught than before.
Mr. Auslin is a scholar at the American Enterprise Institute in Washington and a columnist for wsj.com. Follow him on Twitter @michaelauslin.