There are many, many slave vessels that dump huge amounts of plastic netting into the ocean (a double digit percentage of the pacific garbage patch is discarded fishing nets).
They can do this because it is in international waters, and the law doesn’t apply.
Spy satellites continuously produce proof that this is happening.
Why can’t we have the navy seize the damn boats as part of their training exercises?
The British Admiralty of the 17th and 18th century would have absolutely loved you.
We fraudulently sent trash to Malasia, in breach of western and malasian laws. The local mafia and western firms forgre 'recycling' documents. The trash gets dumped in the ocean.
The mafia kills reporters and journalists thay go in to inveatigate.
Thats why China has banned plastic imports last year, it was an unpoliceable cesspool of crime and western firms were forstering crime in the developing world.
Do you want China to start cruising around the world and arbitrarily enforcing their laws on other citizens?
Oh man… that’s a slippery slope.
Allows you to justify using force against all sorts of non-violent things you don’t like.
See the many examples where aggressive force was used “for the greater good” in the 20th century if you want some spoilers for how that turns out.
But for that specific scenario, yes it is a bad idea for all sorts of reasons. But only because we're just a bunch of animals on a rock and we just can't seem to agree to play nice with each other.
I blame evolution.
There is nothing above the sovereign nations and they are only bound by their treaties, bilateral and multilateral - despite having a name like "United Nations Convention on the Law of the Sea", this is not some law which UN could pass or modify, it's a treaty which is binding only on those who sign it, and any modifications to add extra restrictions it will be binding only to those ships whose countries agree to these restrictions. UN (and any other international organization) is subservient to the sovereign countries or a place of discussion, not some "world government" above them.
We have fishing quotas, ban on testing nuclear weapons, etc.