What if everything is so diffuse that there's no single obvious target, but instead thousands or millions of them? How is a person living in Singapore, for example, going to sue a million different Indonesian farmers for polluting his air?
It's why numerous large organizations exist such as the WTO, UN and so on.
If you have a million farmers causing it, then it has to be elevated to a national level, as an enforcement issue. It becomes no different than if country A were allowing radioactive run-off to flow into country B's territory.
If you then say that those international bodies don't function properly, such that they can't or won't punish Indonesia for failing to stop the mass pollution that is directly harming Singapore, then that is a huge inter-governmental failure that obviously needs to be corrected.
Property rights are enforced at the government level (judicial, police, military), not by corporations. Any failure on protecting property rights, is inherently a governmental failure in one regard or another.
