They'll take you away...
It wasn't there to bite on - it's an opinion that's had 40 years of scepticism to deal with.
I disagree with you entirely. There is no middle ground - it's either kill or do not kill.
Nobody said it would be easy to give up wars and the desire to fight in them, but I don't believe there's a way to legitimise war either. The example of WWII should disspell that forever, because one man's just reason may in fact be a very bad reason.
To avoid politics and stick to history, I'll use the example of Vietnam. The USA felt its reasons for that war were quite legitimate - they were asked to join! Yet, there is no doubt that millions of lives would have not been lost or damaged had they stayed home. All that war did was delay the inevitable victory of the Northern armies and create immense suffering in the region.
There are no "good" reasons for wars. Martin Luther King jnr changed a nation while Mohandas Ghandi reclaimed one - both with a distinctly peaceful approach. It isn't as if we have no examples of pacifism winning.