[simonh]

No it does not. They did not initiate the aggression.

There's a question of semantics here of course. We're contrasting aggressive and defensive military action. I don't see how characterising military action in defence of others as aggressive is a useful or meaningful characterisation. It's defensive, just not defensive of yourself.

Also let's look at the objectives. The intention in Kosovo wasn't to invade Serbia but to end ethnic cleansing. The fact it took force to achieve that was a means to and end, not an end in itself. Without the ethnic cleansing there would have been no military action, so it wasn't about territory or aggression.