As for dictators, they are violating international law. Abortion is legal in the US (withing certain parameters), and international law does not declare it to be illegal either.
International law primarily regards the interactions between nations rather than the actions within a nation. It is debatable whether or not a nation that is non-signatory to a treaty has violated a law when they fail to abide by its precepts.
I think most people would claim that murder is intrinsically wrong, and is not bad merely because it is contrary to some words on a piece of paper.
People can disagree as to what is unjustified; one person might consider a death in an arranged duel to be murder, while another might consider it justified. Under the law of today it is unlawful, under many laws 200 years ago it would be lawful.