That's not what is being discussed here. There is difference between a combat situation as part of warfare and targeted executions of induviduals outside of war.

You must have a much clearer idea as to what 'combat situation' and 'targeted executions outside of war' means than me.

Is it acceptable to bomb a tent of generals planning a campaign in the middle of a war?

Yes; although war has rules. It's not clear whether this is part of a war or not.

Is the United States at war with Yemen? No.

Are the Yemenis being bombed civilians or military? Well, they're not the military of any particular state. We're in a murky territory here now, where the US gets to unilaterally declare war on individuals and deem them "not civilians" so it's ok to bomb them.

This is not a war with a state. That would be much more clear cut.

We are clearly not at war with Yemen. Yemen, the state, is cooperating with US efforts in their country.

The US gets to unilaterally go to war with individuals (that are part of a larger movement that relies on extreme violence against non-combatant civilians to achieve its goals, it is important to remember) because they've unilaterally gone to war with the US.