This week, Scott sat down with his Lawfare colleagues Daniel Byman, Tyler McBrien, and Natalie Orpett to talk through aspects of the week’s biggest Iran-focused news stories, including:

“Situational Iran-y.” The world came into Tuesday evening fearing a major escalation in the ongoing U.S. and Israeli conflict with Iran. But instead, President Trump made a last-minute choice to accept a two-week ceasefire, conditional on the opening of the Strait of Hormuz—a condition that Iran indicated it was prepared to meet, kind of, so long as “open” means coordinating with its military forces (and paying) for safe transit. Is this the beginning of the end of the Iran conflict? And what does the shape of the ceasefire tell us about the conflict’s likely regional implications moving forward?

“Verbal Iran-y.” Tuesday’s breakthrough ceasefire agreement came after days of increasingly outlandish rhetoric by President Trump, including a threat earlier that day that “a whole civilization will die tonight” if his conditions were not met. What role did Trump’s threats play in the outcome? And what might the broader ramifications might be of the U.S. president issuing threats that would amount to war crimes (if not genocide) if actually followed up on?

“Dramatic Iran-y.” While Trump’s rhetoric was undoubtedly intended to communicate strength, it came from a place of increasing weakness. U.S. military operations in Iran were weeks away from a major statutory barrier, and efforts to secure needed supplemental funding are facing headwinds in Congress. Perhaps more importantly, the conflict has proven widely unpopular and devastating for the U.S. and broader global economy—two factors that weigh heavily on Trump and his congressional allies in an election year. What will this shift in the Iran conflict mean for Trump’s political future? Not to mention the legal and institutional arrangements that have allowed him to pursue so unorthodox a foreign policy in recent months?

"jus in belo and "jus ad bellum" are mentioned in this podcast, this is a nice definition of them

https://lieber.westpoint.edu/myth-jus-ad-bellum-jus-in-bello-purity/

In modern international law, the separation of jus ad bellum (the law governing the right to go to war) and jus in bello (the law governing conduct in war) is frequently treated as dogma. For some, this separation is unequivocal, with some going so far as to say jus ad bellum may never “override” jus in bello, even when a State’s only alternative is certain annihilation.

This post argues that although the two bodies of law can and perhaps, in many cases, should be treated separately, the notion that the two must—without exception and whatever the consequences (fiat justicia ruat coelum)—remain absolutely separate, is not just unsettled law, but is legally unsupported.

also see https://www.icrc.org/en/document/what-are-jus-ad-bellum-and-jus-bello-0

Jus ad bellum refers to the conditions under which States may resort to war or to the use of armed force in general. The prohibition against the use of force amongst States and the exceptions to it (self-defence and UN authorization for the use of force), set out in the United Nations Charter of 1945, are the core ingredients of jus ad bellum (see the box titled "On the Prohibition against War").

Jus in bello regulates the conduct of parties engaged in an armed conflict. IHL is synonymous with jus in bello; it seeks to minimize suffering in armed conflicts, notably by protecting and assisting all victims of armed conflict to the greatest extent possible.