This question is prompted by comments on my previous question about the relevance of armed professionals on shipping alters their legal status:
It's not legal for terrorists to attack a merchant ship in transit that isn't attacking or threatening a country, whether or not the ship has some "armed professionals" on it.
I didn't say the government of Yemen would have no right to interfere with the ship.
I get this to mean that an important consideration in determining the legality of attacks is the statehood or otherwise of the entity that carried out the attacks. The accepted criteria of statehood were laid down in the Montevideo Convention in 1933, which provided that a state must possess a permanent population, a defined territory, a government, and the capacity to conduct international relations.
There is a permanent population under the actual control of the Houthis, including the Yemeni capital Sanaa. There are maps of their control, which line up quite well with state borders that were internationally recognised until until quite recently. They have people working in roles that could be called a government, like president and Supreme Political Council and General Corporation for Textile Industry. I THINK they are recognised by Iran, though I cannot find any any good confirmation of that, and are able to communicate and have an influence internationally. I am fairly sure that they themselves consider that they are the legitimate rules of North Yemen at least. The US and much of the rest of the world considered them a terrorist group and recognise the Presidential Leadership Council as legitimate rules of all Yemen.
What effect do any of these facts have on the legality of the attacks on shipping in the Red Sea?