Entrance to Pearl = .5 miles

6KT nuke (as tested by NK in 2006) in the entrance, ground burst

As you can see the 2 line up almost as if they were made for each other. The damage to the harbor, Especially if theyany ship was in transition at the time would make the harbor un-navigable, Not to mention the radiation contamination, The destruction/damage/contamination of the HNL airport, Hickham AFB, Pearl Harbor shipyards, Pacific fleet command, HNL city,
A second bomb of a similar size would also clost Honolulu harbor,
And this dosent even factor into account the fact that they could destroy almost all of Hawaii by using a nuke on the big island. This could create a landslide that would cause a tsunami that would wipe out the hole island change.