Why would Canada return to a war it would rather forget?

Andrew Potter: Afghanistan, the sequel. Why would Canada return to a war it would rather forget?: 

Afghanistan was our most ambitious foreign adventure since the Korean War, but it’s an adventure most Canadians, including their government, seem keen to forget. The American journalist Dexter Filkins wasn’t wrong when he called it The Forever War though, which is why the United States is readying a “mini-surge” of potentially 5,000 troops back into Afghanistan. Once again, they will be asking NATO countries to help out. And as Postmedia’s David Pugliese reported last week, Canada will be asked to chip in.