When you’re being invaded.

Like others have said defensive wars. But I also don’t take issues with a countries that have a brief compulsory service system in times of peace as a means of ensuring a large pool of qualified fighters without a large standing army.

None. It is never acceptable imho.

We do not choose where we are born or the social class we are born into. Forcing someone to sacrifice their life in the name of an entity they did not choose, likely have no/limited loyalty for, or might even be actively oppressed by - is wrong.

I didn’t see it yet, so I’ll say in a humanitarian crisis.

None.

I think that the exact measure of whether or not a war is justified is whether or not people are willing to fight it.

It’s very rare for a war to be a direct threat to the people. That’s generally only the case in a situation like Gaza, in which the invaders explicitly intend to not only take control of the land, but to kill or drive off the current inhabitants.

As a general rule, the goal is simply to assume control over the government, as is the case in Ukraine.

So the war is generally not fought to protect and/or serve the interests of the people directly, but to protect and/or serve the interests of the ruling class. And rather obviously, the ruling class has a vested interest in the people fighting to protect them and/or serve their interests. But the thing is that the people do not necessarily share that interest.

And that, IMO, is exactly why conscription is always wrong. If the people do not feel a need to protect and/or serve the interests of the rulers, then that’s just the way it is. That choice rightly belongs to the people - not to the rulers.