Paul Carroll on CNN.com: North Korea blast tests U.S.

"Pyongyang's action has rightly been condemned as a breach of international law, violating U.N. Security Council resolutions passed in the wake of its earlier test in 2006," writes Ploughshares Fund Program Director Paul Carroll on CNN.com.  "But it is important to focus on two things in the aftermath of the test. First, what does this mean for the threat that North Korea poses to international security? Second, what should our next moves be?"  Carroll says that what is needed is a long-term policy of subtle and creative engagement that stays consistent, especially during difficult times.  He offers President Obama a few suggestions.