The world lives in a Dollar system and when the United States lowered interest rates to deal with its banking meltdown in 2008 the rest of the world had no choice but to follow. The policy that is appropriate for US is not necessarily right for other countries. The household debt to income ratio is approaching 70% (pre-crisis) in the United States but in Canada, Australia and a couple other developed countries it is over 170% and climbing!

https://data.oecd.org/hha/household-debt.htm