It may be wishful thinking, given the unattractiveness of existing options in dealing with North Korea, but there is at least some reason to wonder about the stability of the dictatorship that has lasted almost seven decades.  Most North Korea-watchers dismiss the idea of an organized popular resistance.  The rewards for being an informant and the penalties for saying something that might be construed as criticism of the regime are so severe that organizing seems impractical.

Yet there are signs that vandalism of monuments to the Kim dynasty is a worry.  Julian Ryall reports in the U.K. Telegraph:

North Korea has stepped up security around statues and other larger-than-life monuments to the ruling Kim family, apparently out of concern that they might be vandalised by a disgruntled – and increasingly hungry – citizenry.

Citing its sources within North Korea, the Seoul-based Daily NK news web site said police "have been mobilised for night patrols" around statues dedicated to the three generations of the Kim family that have ruled the nation since 1945, while additional care is being taken across the country to protect wall murals and oil paintings in public places that extol their heroic achievements.

The Daily N.K. has photos showing extra protection:

"Agencies have constantly been saying 'Use lights to illuminate statues and paintings of the three generals of the Mount Paekyu bloodline [the Kim dynasty] and thoroughly care for them to ensure that hostile elements cannot damage them'," a source in Pyongyang told the dissident publication.

From my reading of North Korea, the arrival of video players and software, via air drops and smuggling over the Chinese border, has radically changed many people's minds.  The former isolation may have convinced people that they really were among the world's most fortunate, but supposedly, people now understand the contrast of their own poverty with the wealth of the South.

We know from what we saw in Eastern Europe, especially Romania, that fearsome regimes can crumble in nearly an instant once the possibility becomes real.

There are some wild cards in North Korea that we don't know about.  Three American carrier groups means a lot to the North Korean military and to China, too.  What kind of pressure, and what kind of incentives, is China aiming at Kim, and at the people on whose support he depends?