A New Global Nuclear Order

When North Korea announced its nuclear test last week, it was just the lat­est sign that the effort to con­tain the spread of atom­ic weapons was break­ing down: Sev­er­al coun­tries are on the verge of begin­ning ura­ni­um enrich­ment pro­grams, and oth­ers have already start­ed such efforts, pol­i­cy­mak­ers and experts say.