To be totally frank, I don't really understand the legal requirements from this. Do I really have to comply with all of a country's laws in order to allow its c

To be totally frank, I don't really understand the legal requirements from this. Do I really have to comply with all of a country's laws in order to allow its citizens to purchase electronic goods from my online storefront (assuming I have no physical presence in their country)? If so, why? And what possible sanctions do they have against me? Logic would dictate that the country would be responsible for barring access to such resources from within its borders - not individual foreign bussinesses.