CAMBRIDGE, England — The war of words goes on. U.S. Deputy Defense Secretary Paul Wolfowitz has warned the North Korean government that any aggressive activity on the Korean Peninsula sponsored by North Korea would be met by a "devastating response."

Presumably that is a threat of military action by the United States. At the June 2 press conference in Seoul in which he made the threat, Wolfowitz also said he takes seriously Pyongyang's claims to have developed nuclear weapons. He added, however, that U.S. intelligence is unable to confirm whether North Korea possesses any weapons of mass destruction.

The thing is, the North Korean government has never claimed publicly that it has any nuclear weapons or that it is engaged in uranium enrichment or plutonium production.