Can Intentionally harming another be morally justified?

Of course it is wrong to intentionally harm another person.
You can harm a person by words or by rumour or mobbing - it is wrong
Selfdefense? If someone hits and you hit back - I would accept that.
Selfdefence when you carry a gun or a knife in case something happens
That could be seen as planned intentionally hurting or killing someone
If you are a policeman/woman it is something else.
Harming someone in pursuit of a good end.
How do you know beforehand it is going to be a good end?
You don´t - you can hope and wish and dream.
But knowing - no

Human morality is a rather flexible, slippery thing. Some people, claiming to be involved in a just war, would argue the justice of "collateral damage," the maiming and killing of bystanders (civilians) in the pursuit of military goals. The intentional firebombing of German cities during he second world war is an egregious example of that concept carried to an extreme.

Otherwise, i pretty much feel the same as what Saab has expressed.

Abstractly speaking "collateral damage" is not the issue at hand you dense brick. There is no direct tangible mechanical moral relation between intentionally harming X and harming X as a statistical collateral effect of some other goal which was unpredictable. On the other hand choosing to shot down a plane full of innocents with a terrorist in control is a moral dilemma. Is that "collateral" in your lingo ? Justification comes from the least harmful outcome between the lesser of two evils. If you think moral is a slippery thing because its complex beyond man ability to deal with it then you excused moral responsibility.
By the way bombing German cities was "collateral" only in the written policy of war winners. When you freaking press the button to bomb hundreds of thousands innocents you get collateral **** for thinking with your ass.You inverted the pyramid of good justification.

Slaps ticking time bomb out of someone's hands.

Bomb falls into nearby ocean, conveniently located below a nearby cliff.

Boom.

Humans safe.

Bonus: free fish dinners for all.

You mean sardine soup right ?