What exactly means "Teroristic Act" and who is able to legally confirm it?

Question

Regarding new geopolitics situation in the world, especially in chartering, if some fool attack some vsl with havy weapon it is probably not Teroristic Act, but who is in charge to define some attack as Teroristic Act from the legal point of view? This is very important also from the insurance point of view. Let's imagine such situation in international waters without any state jurisdiction! Maritime laws did not define such situation well. Many insurance companies under Force Majeure recognise only if some state's authorities proclaims Force Majeure. Lot of idiots, heavy armed, walk, fly or travel with vsl and could do some stupid thing in any given time with or without reason - although there cannot exists reason for attacking even one person! This question is pure technical issue. How would Lloyd react if they asses that there were no terrorism? But vsl is damaged, lives are lost or endengareous.