The "only" problem

Ed. here. I was reading a little essay on the War of 1812 -- the only war the USA lost until Vietnam -- and came upon this sentence:
The war is only part of [Canadian] history because the Americans and the British decided to work out their differences on our land.

What does the writer (Barbara Smith) mean by "The war is only part of [Canadian] history..." Does she mean there's more, as in "only a part of [Canadian] history"? Or does she mean the war is a part of Canadian history only because...

The word "only" is like a penis. You have to be careful where you stick it. You must take care to place it immediately before the noun, verb or adjective you wish to modify because to put it close to some other word can change the whole meaning of your sentence. Here are some examples:

Only I told you I killed my wife. = No-one else told you.
I only told you I killed my wife. = I didn't put it in writing.
I told only you I killed my wife. = I didn't tell anyone else.
I told you only I killed my wife. = Nobody helped me.
I told you I only killed my wife. = I didn't do anything else to her.
I told you I killed only my wife. = No-one else.
I told you I killed my only wife. = I'm not a Muslim.

Thus endeth the only lesson... for today. You're welcome.