The Legality of a "Vulcan Hello"
Klingons. Shit. The Captain sure is good at finding interesting things for me to research, but this case is pretty intense. We had just arrived at a binary star system to repair a broken communications relay. First officer Cmdr. Burnham and Science officer Lt. Cmdr. Saru were immediately on alert, as it seemed that the relay was sabotaged, not just broken. As we scanned the area, we found... something. We couldn't tell what it was, and wanted to check it out. In the recesses of my mind I recalled an old custom from Earth's maritime law, where ships are obligated to render aid on the open ocean. The similarities between us in interstellar space and a sailor on earth a few hundred years ago are significant, so I figured that the rationale still held, and told the Captain that we could go ahead and investigate. After all, our limited precedent out here has various instances of Federation ships helping others1 Besides, the object was inside Federation space.
The situation spun out of control after that. A bunch of Klingon ships arrived and things were not looking good. Generally, Starfleet ships are not warships. We do not attack but only defend ourselves. But that does not mean that we have to wait to be attacked! And the Klingon's arrival had already breached our peace treaty and interstellar law. They were in our territory! At least that is what myself and Cmdr. Burnham tried to tell the Captain. Burnham apparently knew of the Vulcan history with the Klingons and that they used violence whenever they ran across the Klingons. But I was just like "um... they're already in our territory, they've already destroyed our communication beacon, and they've already attacked our first officer! We can defend ourselves!"
Even if the Klingons hadn't already violated Federation territory and attacked, we still were legally justified in defending ourselves with a pre-emptive strike. I get that we Earthlings have a long history of abusing the doctrine of self-defense, even inventing the idea of "anticipatory self-defense,"3 but in this case it would have been permitted under almost any reading of law governing the use of force.
Let's assume for a second that the Klingons had not already crossed our border and attacked our officer. It was still necessary to defend ourselves because the Klingon attack towards us was "instant, overwhelming, and [left] no choice of means, and no moment for deliberation."4 We initially had a few minutes to deliberate, but as the Klingon fleet warped into the system, it became clear that the Klingons were going to attack. I told the Captain that the Klingon ships already here was already an armed attack. And under every known system of laws, we were justified to fire. I'm just the ship's lawyer, but we should have shot first, it would have been the right move and it would have been justified. (Plus, it worked out for Captain Solo.) Cmdr. Burnham was right.
2 Which would be a pretty good band name, "Everybody put your hands together for the Thruster Suits!"↩
3 For example, a few strong governments of Earth got together under a trumped up charge of possessing nuclear weapons to invade another country that had a large amount of energy reserves. Boy, the things they did for power back then.↩
4 Webster, Daniel, "Letter to Henry Stephen Fox." (1841); see also literally any book that mentions the "Caroline Incident."↩