An excerpt from Prof. Goldsmith's post at Executive Functions:
We're already seeing a debate about the legality of President Trump's use of force in Iran. I've grown cynical about these debates. Law is the language we use when criticizing presidential war powers—and it has been since the beginning of the nation. But the truth is that there are only political constraints.
As I've been saying for a while, there are no effective legal limitations within the executive branch. And courts have never gotten involved in articulating constraints in this context. That leaves Congress and the American people. They have occasionally risen up to constrain the president's deployment of troops and uses of force—for example, in Vietnam, and in Lebanon in 1983, and in Somalia in 1993. But those actions are rare and tend only to happen once there is disaster.
The Office of Legal Counsel opinions on the presidential use of force are famously promiscuously permissive. Some will now invoke the single acknowledged OLC limitation on unilateral uses of force to criticize the Iran attack. As the opinion justifying the attack on ISIS in 2014 explained: If the "'anticipated nature, scope, and duration' of the planned military operations, analyzed in light of the applicable historical precedent" amount to "war," the president must secure prior congressional approval.
President Trump in his statement about the attack said: "The lives of courageous American heroes may be lost, and we may have casualties," and that "that often happens in war." Does that implicate the OLC limitation and require him to seek congressional approval? It would be very easy for OLC to conclude not.
