Glenn Greenwald alleges that the Bush administration attempted to expand executive power, as evidenced by the unitary executive theory propagated by John Yoo. The theory suggests that the President, as Commander-in-Chief, cannot be bound by Congress or any law, national or international. By invoking the state secrets privilege in cases involving actions taken in the war on terror (i.e. extraordinary rendition, allegations of torture, allegedly violating the Foreign Intelligence Surveillance Act), Greenwald opines the administration tried to evade judicial review of these claims of exceptional war powers. In effect, this is preventing a judicial ruling determining whether there is a legal basis for such expansive executive power. With that in mind, applying this privilege makes impeachment the only possible means left for Congress to exercise their duty to uphold the checks and balances constitutionally intended to prevent abuse of power.