I just began reading the book "Pachinko," and it starts thus:

>   History failed us, but no matter.
>
>   At the turn of the century, an
> aging fisherman and his wife decided to take in lodgers for extra
> money. Both were born and raised in the fishing village of Yeongdo--a
> five-mile-wide islet beside the port city of Busan. In there long
> marriage, the wife gave birth to three sons, but only Hoonie, the
> eldest and the weakest one, survived. ....

For more information, let me share part from the recommendation remark for this book.


>   Pachinko represents a breakthrough portrayal of an invisible society
> within a society--Koreans in Japan. The book begins with the sentence,
> "History has failed us, but no matter." That is one of the most
> succinct summaries of the twentieth century's legacy of colonialism
> and war that still fuels tensions in North East Asia, including the
> current crisis with North Korea.

"Fail" is always a difficult word to me when it is used in the forms like 
"failed me" or "failed us". Please explain what the whole sentence "History failed us, but no matter" means.

Plus, there is another "fail" phrase which I want to know correctly.

> The poor men mocked their powerful colonizer within the shabby walls
> of the boardinghouse, feeling secure from the colonial police, who
> wouldn't bother with fishermen with grandiose ideas. The brothers
> boasted of China's strengths--their hearts yearning for another nation
> to be strong since **their own rulers had failed them**. Korea had been
> colonized for twenty-two years already. The younger two had never
> lived in a Korea that wasn't ruled by Japan.

In the context, I understand that the "*fail*" in "**their own rulers had failed them**" implies their own rulers(Japanese rulers) had colonized them(Koreans) or that Japanese imperialists had kind of defeated Koreans. I want to know the exact meaning though.