Question

No one is on history sooo
Which explains why U.S. leaders are eager to get North Korea to sign the Nuclear Nonproliferation Treaty?
North Korea has targeted U.S. allies with threats of nuclear attacks and ultimate destruction.
North Korea has launched a nuclear attack against the United States in the past.
North Korea has demonstrated that it has access to more nuclear weapons than any other country.
North Korea has the ability to fire a nuclear weapon that could reach U.S. territory.