Yes it is paranoid and hypocritical of the USA and other imperialist countries to condemn the DPRK for testing a nuclear weapon. All countries - including small ones - have the right to defend themselves against attacks or invasions by aggressive warmongers.
It makes peace and security more likely in Korea, because the USA now knows that any nuclear attack on the DPRK will be met with like-for-like retailiation. If the USA is determined to destroy the socialist system of the DPRK, then so be it - but the DPRK will go down fighting and will take some of the imperilaist powers with it. The people and army of the DPRK, under the steadfast leadership of the WPK and the glorious leadership of the Dear Leader Kim Jong-Il, are united in determination to maintain the independence and self-determination of the DPRK.
It should be remembered that it is the USA, not the DPRK, which has (a) used nuclear weapons in warfare (b) threatened to use them as a first-use basis (c) invaded and bombed other countries (d) sold nuclear technology to other countries.
Long live the Democratic People's Republic of Korea!
Long Live the Workers' Party of Korea!
Long Live Kim Jong-il!
Celebrate the 80th anniversary of the Down-With-Imperialism Union!