Normally false flags means, that the country, which flag was choosen for false flag, get some very little fee of false flagging.
If travelling under Tonga Island flag, the authority over the ship is in Toga, if it's rent from Tongo to another shipping company, e.g. a chinese company or an american logistics and transport company.the US or chinese company had to pay a cheap fee for renting the boat!
If a ship with a flag, where the country of the flag gets no money at all (nothing), .but is held full accountable in case of problems or legal violations involving the ship, is always the same drama.
But, a government can order all ships under its flag to home port in case of uprising conflict or war or in case of international emergency.
Since the syrian government is a partner of the west, I would advise to immediately order it to home port, because Hezbollah could have used the ship as secrets waepons camp and all ships, that leaved under Assad syrian home port must be checked, because they could have items for IRG or Hezbollah on board and must be cleared.