Ironically, many activists will probably hope that the ship is a warship, not some fuel tanker or hospital ship. That would make the "non-victory" even sweeter - re-entry on New Zealand's terms.
The only people who won't be happy will be the die-hard anti-Americans; and perhaps those in the Y generation who have no grasp of history.
The New Zealand Navy's 75th birthday invitation for a ship visit has given the Obama Administration an opportunity to end an absurdity prolonged by the US Navy long after the political wounds had been healed.
The ban was an absurdity that until 2012 saw the United States have greater military contact with countries it barely called acquaintances, let alone very, very, very good friends.
The Americans could have come back at any time.
New Zealand law has never banned US ships. It requires the New Zealand Prime Minister to be certain that any visiting ship complies with New Zealand law prohibiting nuclear armed or propelled vessels.
It does not require New Zealand to ask the question.
It does not require the Americans to confirm or deny anything.
It requires skilled officials to look up Jane's Fighting Ships on Google and inform the Prime Minister whether a specific vessel is nuclear armed or powered.