In December 2008, in its final hours, George W. Bush’s administration signed with Iraq a Strategic Framework Agreement that was, Webb says, “not quite a treaty,” which would require two-thirds approval by the Senate, but neither was it merely implementing current policy and law. It outlined the U.S. role in defending Iraq from internal and external threats, in promoting reconciliation and combating terrorist groups…

Noting that, in foreign as well as domestic policy, Obama is “acutely fond of executive orders designed to circumvent the legislative process,” Webb recalls that in 2009 the administration said it would return from the United Nations’s Copenhagen conference on climate change with a “binding” commitment for an emission-reduction program. So Webb wrote to remind the president that “only specific legislation agreed upon in the Congress, or a treaty ratified by the Senate, could actually create such a commitment.”

Webb notes that presidents now act as though they have become de facto prime ministers, unconstrained by the separation of powers.