I am not disingenuous in asking them.

I'm not even necessarily talking about the current situation here.

I'm asking you, where your line in the sand is.

If someone was in your home, threatening your life, or your loved one's lives, and they absolutely were not empty threats, would violence to the point of killing be "justified"?

For example, should the Ukrainians not defend their sovereignty, on their own soil, because killing at all is immoral?

You came at this with a black and white statement, but there are nuances to the world that shape the decisions outside of a binary "they killed/didn't kill"

If one side kills 100 for each one of their own killed there's a big difference. Other factors to consider is when your land is blocked off from the outside world by land, sea and air and being routinely invaded. The Geneva convention says there is a right to resist occupation on top of that which Israel did sign.