The initial joy that erupted in Hailey and across America when President Barack Obama announced that he had secured the freedom of Sgt. Bowe Bergdahl, has been overshadowed by the controversy surrounding the illegality of the president's action. In plain terms, President Obama violated a statutory requirement integral to the prisoner swap that won the release of Bergdahl. The administration's defense on constitutional grounds, moreover, is weak and unpersuasive. Fortunately, a constitutional remedy is available.

President Obama flaunted a law, passed in 2013, which requires the president to notify Congress, "not later than 30 days before the transfer or release" of prisoners from Guantanamo Bay. The administration has advanced shifting lines of argument to justify this evasion.

First, it relied on the signing statement that Obama appended to that law, indicating that he believed the notice requirement deprived him of the necessary "flexibility" to "swiftly" conduct negotiations involving the transfer of detainees at Guantanamo. Obama declared that the window of opportunity to obtain the release of Bergdahl was rapidly closing.

Second, a National Security Council memo asserted authority for the president as commander in chief to protect "the lives of Americans abroad," including "U.S. soldiers."

President Obama's resort to the use of a signing statement to ignore parts of laws that he doesn't like is an exercise in hypocrisy. As a presidential candidate in 2007, Obama criticized President George W. Bush for using signing statements in that manner. As a principle, there is nothing wrong with presidents issuing a signing statement to explain how they will enforce congressional aims. But Obama has used it as an instrument to circumvent the will of Congress, the very behavior for which he criticized President Bush.

Obama's assertion of constitutional authority to protect U.S. soldiers is too broad. The president shares with Congress constitutional authority over U.S. soldiers. The enumerated powers granted to Congress are much greater than the Article II Commander in Chief authority. With the exception of repelling an invasion, the commander in chief's powers are derived from congressional grants of authority.

The Constitution confers sweeping powers upon Congress. The specific grants include, among others, making rules "concerning Captures on Land and Water," raising and supporting armies, providing and maintaining a navy, and "regulation of the land and naval Forces." The president's powers pale in comparison to those vested in Congress.

Let's assume for the sake of argument that President Obama was correct that his administration had to act quickly to win the release of Bergdahl. Those circumstances, by themselves, didn't provide legal justification for the president's action. However, the White House - or Congress - might still make the president's action legal by invoking the doctrine of retroactive authorization, the preference of the framers of the Constitution for meeting emergencies.

The framers refused to clothe the president with an emergency power, fearing that such authority would tend to kindle emergencies. A congressional grant of retroactive authorization, making an illegal presidential action legal after the fact was a preferred approach since it placed Congress in a position to judge the rationale behind the president's illegal act. President Lincoln sought - and received - such authority from Congress to "cure" the unconstitutional acts he had committed during the Civil War.

At this juncture, Obama's statutory violation could be remedied if Congress were to grant retroactive authorization, confirming the wisdom of his decision to obtain freedom for Sgt. Bergdahl. Idaho's congressional delegation could lead the way by introducing the appropriate legislation to remove the shadow of illegality that clouds the joy surrounding Sgt. Bergdahl's release.

David Adler is the director of the Andrus Center for Public Policy at Boise State University, where he holds appointment as the Cecil D. Andrus Professor of Public Affairs.