William Shakespeare said that 'all the world's a stage', but when it comes to international law, who are the actors?
Well, for a long time, the only actors were nation-states.
Some states are larger than others, but in theory all sovereign states are equal under international law.
As lawyers would say, states have legal personality, so they can sign treaties and do other things, but well, things don't always work out.
So, after the destruction of World War Two, new faces emerged, including international organisations, like the UN.
They helped states agree on laws to stop them fighting, to agree basic human rights and to start working together.
NGOs also joined the stage to champion causes, like the environment and human rights.
But another group of actors was warming up behind the curtain: the multinational corporations.
In our interconnected world, some of these actually play bigger roles than the smaller states.
So, this is where we are now: the stage is crowded, which can make the action a bit hard to follow.