In 1971, barges loaded with sand arrived from Australia, bringing the reef level above the water and allowing construction of a small tower and flag. The Republic of Minerva issued a declaration of independence on 19 January 1972 in letters to neighboring countries and even created their own currency...
A Tongan expedition was sent to enforce the claim the following day. It reached North Minerva on 18 June 1972. The Flag of the Tonga was raised on 19 June 1972 on North Minerva and on South Minerva on 21 June 1972.
Apparently there was another attempt a decade later, also rebuffed by force:
In 1982, a group of Americans led again by Morris C. “Bud” Davis tried to occupy the reefs, but were forced off by Tongan troops after three weeks.
So why bother? The whole project strikes me as a dead on arrival. Wikipedia quotes Reason as saying that even the reefs themselves have evidently been "reclaimed by the sea." Were the Tongans afraid of a slippery slope (Today Minerva, tomorrow Polynesia!)?
This was one of several projects undertaken by the radical libertarian group the Phoenix Foundation. A group whom I've always thought would make an excellent Bond villain.
The goal of the Foundation-- in this project as in others (secession in the Bahamas and the New Hebrides/Vanuatu), was to create a tax paradise where companies could be based and eventually to create a place where manufacturing could be untaken without any sort of regulation or hinderance. The creation of Minerva was their first real Pacific adventure and one of the more spectacular perhaps as they ferried equipment across the Pacific to establish the island.
The Phoenix Foundation had fairly extensive monetary backing by real estate tycoon Michael Oliver and Harry D. Schultz, the philosophical force behind the group. Shultz believed (and might still, I'm not current on his writings) that micro nations (or at least smaller nations) were the only viable economic model for the future, that large governments were too slow and too wasteful.
As this group began establishing their new nation in the middle of the Pacific, in waters claimed by Tonga, and on reefs used by Tongan fishermen, it was fairly clear that action had to be taken lest it invite future attempts of this nature. And the threat was very real, the Phoenix Foundation had money and backing and was determined to establish their free market paradise. So much so, that this would not be their last attempt at doing so, though in the future they tended to work with existing secessionist groups such as NaGriamel or Jimmy Stevens in 1980 on the New Hebrides. Their strategy in this was to take advantage of the moment of independence to try and wrest an island away from the young nation of Vanuatu.
The only book I know of that has more extensive coverage of the topic is "Blood on their Banners" by David Robie. Robie discusses the events surrounding 1972 but primarily he is writing about Vanuatu and so discusses their 1980 effort in greater detail. In general their actions in Vanuatu have been covered a lot more as the whole event was far more complicated and messy than just the involvement of the Phoenix Foundation.
Wait. They sent out a boat to respond January 20th and it arrived June 18th? Is that correct?