Yeah the humanist in me also says that we need to send more Australians over there to kill more Afghanis.

The second part of what you said is ridiculous.
No, it's not ridiculous at all in my opinion. Even with huge pressure from the coalition forces and tens of thousands of foreign troops in his country, Karzai is
still making overtures to the Taliban.
So let's picture this - pull out all the troops. I am willing to bet my house that in that situation, within a few years, the Taliban would be back in power and the Afghan people under the thumb of their regime again (strict Sharia law, if I need remind you). Take it the other way - more soldiers means more stability, a happier Afghanistan and a stronger Afghanistan, given my claim that sending more troops is in fact better for humanity. And please don't make the distinction that I love war, I don't, I just know that it can be a solution sometimes.
Take Iraq, that was a giant turd speeding towards its inevitable doom (at a rate of 40 attacks
a day), Bush sent a largely unpopular troop surge there (of course Obama is allowed to do one without much of a backlash, but ok) and the attacks dropped significantly within a year to around 4 attacks a day and even now, with many troops being pulled out, to around 4 a month. Troop surge = happier country.