''on'' or ''of''?

"Where there are no such laws, the burden of upholding the principles of justice and common decency falls on the ordinary people. It is the cumulative effect on their sustained effort and steady endurance which will change a nation where reason and conscience are warped by fear into one where legal rules exist to promote man's desire for harmony and justice while restraining the less desirable destructive traits in his nature."

The above paragraph was part of a speech by Ang San Suu Kyi. I suspet the proposition 'on' is a misprint, and it should be 'of', which makes more sense in the context.

What you think?

Thanks in advance.