here continuing to resource the O'Connell arguments in opposition to my conclusions (and the current USG position) ...

Combatants and the Combat Zone, Mary Ellen O'Connell, Notre Dame Law School, January 23, 2009

Abstract:

Following the attacks of 9/11, President George W. Bush declared that the United States was in a "global war on terrorism". His administration claimed the wartime privileges to kill without warning and detain without trial anyone suspected of association with terrorist organizations anywhere in the world. These claims were made in the face of contrary international law. Under international law, a war or armed conflict is characterized by organized armed groups engaged in intense, armed hostilities. To meet these criteria, such groups are associated with territory. In addition to the concept of armed conflict, the concept of conflict zone is important. Killing combatants or detaining them without trial may be permissible when done in a zone of actual armed hostilities. Outside such a zone, however, authorities must attempt to arrest a suspect and only target to kill those who pose an immediate lethal threat and refuse to surrender.
Preserving the Peace: The Continuing Ban on War between States, Mary Ellen O'Connell, Notre Dame Law School, July 22, 2008

Abstract:

The history of international law is, in large part, about the development of restraints on states' right to resort to force in dealing with external conflicts. Today, states may use force only in self-defense to an armed attack or with Security Council authorization. Even in these cases, states may use force only as a last resort, and then only if doing so will not disproportionately harm civilians, their property, or the natural environment. These rules restricting force are found in treaties (especially the United Nations Charter), customary international law, and the general principles of international law. In other words, the three primary sources of international law yield important rules restricting the use of force. The rules on use of force, like all international law rules, are binding on states for the same reason the law of any jurisdiction binds - because it is accepted as law by the community.

The following remarks on the rules regulating the use of force are divided into three parts. Part I provides a brief history and overview of the current rules on the use of force. Part II applies these rules to assertions that the United States could lawfully attack Iran today. Part III then discusses why these rules are binding as law and answers arguments to the contrary. These remarks will, therefore, touch on the past, present, and future of the law on the use of force to preserve the peace between states.
The Myth of Preemptive Self-Defense, Mary Ellen O’Connell, Professor of Law, The Moritz College of Law and Associate of the Mershon Center for International Security and Public Policy, The Ohio State University, August 2002 (emphasis added):

Conclusion

The international law of self-defense supports the American use of force in Afghanistan. After the devastating attacks of September 11, the United States had the right to defend itself against continuing terrorist attacks mounted from Afghan territory. The United States has no right, however, to invade another state because of speculative concerns about that state's possible future actions. The current international order does not support a special status for the United States or a singular right to exempt itself from the law. To maintain a legal order that restrains other states and to uphold the rule of law, the United States should continue its conservative commitment to limits on the unilateral use of force, and reject a reckless doctrine of preemptive self-defense.
In this almost decade-old article, some commonality does exist (the first two sentences) - but I would present a different editorial slant (vs the rest of her conclusion).

But not here, since that would get into my beliefs summarized as "Never Again, but..."; and require regression back into the later 1970s and what I believed ought to have been done then. What would have happened is pure speculation and that regression will not be made.

Regards

Mike