How would capturing a satellite from orbit be any different than a soldier walking up to an enemy's position and driving off with a tank or flying a jet out from under their nose? Some shit would definitely be on the fan at that point.

A better analogy might be detaining a ship or in international waters or implementing a blockade such as the Cuban missile crisis. It is technically casus belli, but rarely does it get escalated that far. Rational actors don't really want to start a war over an incident that doesn't even involve their sovereign territory.

I don't think a blockade is the same thing though. A blockade just prevents a ship from going to the destination or the route it was wanting. It is still free to maneuver and is still in control of the flag it operates under.

That's what I mean exactly.

I'm glad we were never in the situation where this would have been thinkable. Because it would mean direct war between superpowers.