Exactly. Can you imagine if Saudi Arabia tried to have you extradited for a crime that was illegal there, but legal here? On a side note, isn’t that what’s happening with Kim Dotcom?

Without a legal background or at least an understanding of the legal force of treaties, what you’re saying sounds both alarming and vile. In the context of treaties though, agreed upon by governments subject to recall, elections, and separation of powers is the foundation of modern diplomacy. As we’ve seen with Brexit, treaties and laws are both subject to oversight by the electorate, for better or worse.

Beyond that the reason you can’t be extradited to Saudi Arabia is that few countries have such treaties with them. It’s true that the US uses it’s military and monetary power to shove unfavorable conditions where possible, but that’s a universal feature of powerful nations, see China for clarification. Such treaty obligations can lead to problems like the persecution of Kim Dotcom, but it also leads to confrontations over human rights and fairness of laws.

Treaty obligations within Europe prevent them from extraditing someone for a capital crime in a other country. Being outside of binding web of treaties offers freedom, but it often offers the most freedom to dictators. So yes, US copyright law is a mess, and that mess spreads through treaties. That’s a problem with US law, not the concept of treaties.

Most of all, such treaties offer avenues other than violence for countries to settle disputes, and that value can not be overstated.