The only person abandoning logical thought is you. If Tu Quoque can be used as a legal argument legitimately in some situations and is accepted as such by legal scholars then clearly it is not always invalid as an argument. I'm just pointing out that you don't understand the concept and the way you use it is invalid. This is not a blanket defense of any Israeli actions. In some cases the Tu Quoque defense might be appropriate, in others it might not be.
Saudi-backed forces advance on rebel-held province in Yemen (DPA)
from the article: Patriotism sans borders