What is the point in international law if we aren’t going to enforce it?

We see a number of countries committing war crimes, breaking international law etc at the moment. The news reports it and politicians simply condemn it. What is the point in these laws if all we’re going to do is wave a finger and say naughty naughty?

Who is responsible for enforcing it and why is it fair game for them to break international law but not us, the general public, to break weird small laws and bylaws?