According to the North Atlantic Treaty, NATO is indeed intended as a defensive organisation. It got involved in Kosovo, that is true, but that decision was made back then under the impression of the recently finished Yugoslavian civil war that came with various genocidal crimes. Srebrenica might ring a bell.
A repeat of this was feared and deemed intolerable, so the NATO countries indeed exceeded the scope of their organisation for a cause they agreed upon as worthy.
The other part of the deleted post saying that NATO was not there to cater for every whim of the US president has noticeably gone unchallenged, so I trust it to be general consensus on here.