The first seasteads will operate under the same maritime laws as existing ships... Although [cruise] companies have major operations within U.S. territorial waters, the U.S. does not interfere very much with their operations. This is due, in part, to the fact that cruise lines bring in jobs and revenue to the U.S. economy. If the U.S. were to try to interfere too much, the cruise lines would simply move their operations elsewhere. Similarly, seasteads will trade extensively with land-based businesses. The people who profit from those relationships will encourage their government not to interfere and drive away the seasteads business.
LOL That's classic. Because the economic bolstering of doing business with a community of a couple thousand people (at most) definitely outweighs the advantage of simply blockading food from the community and then seizing all the assets.
There's a lot of assets to gain from invading Switzerland too, it doesn't stop small countries from existing. What if the couple of thousand people pay taxes for defense, making the cost of invasion outweigh the assets?
Switzerland is a mountainous, land-locked country of almost 8 MILLION people that is plenty capable of defending itself and also capable of sustaining itself.
How you think you can compare that to an oil rig of maybe 1,000 people sitting in the middle of the ocean and relying on importation of... everything... is mind boggling. These people would be, in quite a literal sense, sitting ducks.