State A is a small island nation, with a large and strategic port that provides a safe haven for sea-weary ships, sailors and trade. State A has been a disputed territory since the 1800's. After many decades of war and with persistence, State A acquired its statehood in 2021 declaring independence from another island nation called State B. (You can assume the criteria for statehood have been met). State A has since joined the United Nations (UN) and has become a party to many of the UN's Conventions.

State B is yet to recognise State A's statehood. State B claims that it has effectively occupied State A since time immemorial. State A disputes this, claiming they are the original inhabitants of the island nation.

Across the vast ocean lies another nation called State C. State C has for decades expressed concern for the potential for conflict between State A and State B. State C has significant natural gas interests in State A.

It is well known that State C provides military support to State A, both on the ground, training soldiers and at sea, with naval patrols. State B claims that the naval patrols by State C are a threat to their territorial integrity. State B has advised State C that military action will be taken the next time naval patrol boats are in the State B's territorial waters.

Meanwhile after months of secret meetings, rebel forces from State B are planning a coup d'etat to over-throw the State A's government. On the eve of the planned attack, 150 rebels enter State A by sea. At the same time, an State C naval ship is moored at the main port in State A after friendly war game manoeuvres with the State A's navy.

While secretly marching to the capital of State A, the rebel forces are exposed by military intelligence and are involved in a shoot-out with State A's special forces. There are many casualties. Despite the bloodshed, the State A soldiers arrest and detain 20 rebel soldiers involved in the incident. A further 55 rebels make it back to the frigate that is moored in the internal waters of State A.

State B is notified by State A diplomatic correspondence, that 55 nationals are being detained and questioned about the incursion on the territory of a sovereign nation. The government of State B has asked for their soldiers to be released, declaring they had no knowledge of the activities of the rebels.

State B has gathered intelligence suggesting that the rebels (who are State B nationals) are being tortured for information by General Meanie from State A's military. This accusation is denied by State A. However, a mole called Dr Astrange has released graphic footage to the contrary. Acts of violence, experimentation and ill-treatment of the soldiers are evident in the footage. State A's government refuses to release the State B nationals.

What issues of international law arise from this scenario?