Not all scholars agree that Federalist No. 70 justifies the role that the President has played in the war on terror up to this point. Some scholars contend that President Bush's foreign policy decisions exceeded his presidential powers granted by the Constitution. Further, critics of the Bush Administration argue that any executive, as envisioned by Alexander Hamilton in Federalist No. 70, must act within the limits imposed by other provisions of the United States Constitution and that the concept of the unitary executive does not allow the president to work outside laws passed by Congress, even when they conflict with national security interests. These critics argue that President Bush could have asked Congress to amend existing law or retroactively obtain warrants for surveillance and that he violated the constitution when he did not. President Obama has been similarly criticized for operating outside the law, despite statements at the beginning of his presidency which showed a desire to limit the use of signing statements to expand executive power.