Actually Xjramper was close on the topic.
Twain was speaking about the Philippine Insurrection 1898-1902.
It's similarities to the current Iraq Insurrection are striking. As well as the differences.
The US won the first war against one organized enemy only to find itself fighting over the same territory with Insurgents.
It was fought with a mixture of Active and reserve units.
US Casualties were around 5000.
Civilian casualties were exponentially higher.
It was generally opposed by the American public.
For all its parallels there are some major differences:
The war in the Philippines was for Empire. Iraq is not.
The war in the Philippines was against a single Insurgent force fighting for Philippine Independence.
Filipinos were not generally killing one another.
Sometimes the Philippine Insurrection is grouped with the Moro Insurrection which ran concurrently and lasted until 1913. BTW the Moro insurgents were Muslim.
Anyway, I just thought I share that quote with you all.
I'm doing some scholarly work on the Philippine Insurrection, as it compares and contrasts with current events. As you can imagine their isn't alot on the Insurrection. i'm only just beginning the work as well. but I ran across that quote and thought it would be fun to share, not matter what you think of the war.
A little less Hooah, and a little more Dooah.