For me, as I said to 500N privately, it's not complicated.
In the sense that all wars are a result of human failure, there can't be justification. But once initiated, there is sometimes no alternative to the opposition of outright tyranny when sovereignty is threatened - that, in my view, is both justifiable and honourable. I thought the programme was well produced, and provided a balanced one-hour view for my grandchildren to contemplate upon later.