International Law replaced the former terminology of 'Droit De Gens' (Trans : Law of Nations) in the first half of the 19th century, from then until the end of WW2 international law was plainly defined as

the law governing relations between states amongst each other.

However after post-WW2 numerous large actors without the representation of statehood became involved in international relations the definition of international law had to be broader and more extended.
This change of definition was given credence by the American Law Institute, which stated: international law

"comprises of rules and principles of general application dealing with the conduct of states and of international organizations and with their relations inter se, as well as with some of their relations with persons, whether natural or juridical"

Anyone who disputes the existence of International Law (read the above write-up) for the lack of an international court to cast judgements under the mandate of international law should note the International Court of Justice, the European Court of Justice, the European Court of Human Rights, the Hague, Nuremburg and Rwanda tribunals all casting criminal and civil judgements most of which have been obeyed. Also if International Law didn't exist, then an awful lot of lawyers, publicists and lecturers would be making an an awful amount of money for a topic that didn't exist.

However if one means that the application of Court judgements are relative in terms of power in capture, and power of non-acceptance that is a valid comment. To suggest from this that international law does not exist because of the varying power held by international actors, would be as nonsensical as saying national law doesn't exist because certain citizens (e.g. Mr Bigs, Kings and Dictators) can ignore and avoid the national enforcement agencies.

*Under new EU police co-operation treaties signed in the aftermath of the September 11th attacks soon, on paper at least, France will be able to send it's police forces to Sweden with full jurisdiction. Response the WU above: Just a very quick response which I may extend later.

1. You seem to be changing your argument from "there is no such thing as international law" to "there is no such thing as a law that governs more than one state at a time, involuntary".
2. If the EU Parliament does pass a law which is not voluntarily incorporated into national law by national parliament, the renegade EU state will be sanctioned and punished by other EU authorities. When France refused to accept British beef imports the Commission threatened it with heavy fines. A state could leave the EU, but that is irrelevent to arguments here. EU Institutions are getting stronger and more firmly embedded every year. (NB: perhaps I should do a node on the Europe Union Consitution Convention headed by Valerie Giscard explaining some of the proposals.)
3. The AAL would be most hurt to hear that.
4. There is such a thing as international law.
5) More later, sorry I know this is put together in a very hotchpotch way.