Who are the "masters of the treaty"? European governments and the European Court of Justice

To what extent can the European Court of Justice, an international court, make decisions that go against the interests of European Union member states? Neofunctionalist accounts imply that because the Court is a legal body it has vast political autonomy from the member states, whereas neorealist accounts imply that because member states can sanction the ECJ, the Court has no significant political autonomy. Neither theory can explain why the Court, which was once politically weak and did not stray far from the interests of European governments, now boldly rules against their interests. In explaining how the Court escaped member state control, this article develops a general hypothesis of the autonomy of the ECJ, focusing on how differing time horizons of political and judicial actors, support for the Court within the national judiciaries, and decision-making rules at the supranational level limit the member states' ability to control the Court.