It’s odd but it has just struck me that despite knowing this quote since childhood it has never occured to me that the final sentence ‘…they must be fought’ could mean taking up arms.

I have always interpreted it as meaning fighting with our minds, fighting with our words and fighting metaphorically.

I imagine a large part of this is down to Patrick’s portrayal of the Doctor. A Doctor who uses his mind, a Doctor who, while seeming whimsical, is made of a granite resolve and a fierce intelligence.
I certainly don’t see him as a warmonger.

Violence in response to violence only breeds more violence, and the Second Doctor certainly knew this.
He also knew that we can fight in other ways. By science and education. By knowledge and resolve.

Physical violence should only be a final solution, never the first option.

Of course the Doctor has used violence many times over the years. Even the very first Doctor wasn’t averse to clonking folk over the head with the nearest heavy impliment, and yes it is often necessary. The Doctor (nor i) am nieve enough to think we can live without violence. There will always be those willing to use violence from the outset, and sometimes there can only be an equally forceful response. But let’s look for alternatives first eh?