There has been a lot of discussion lately about how effective monetary policy can be.
In my view, the big debate between fiscal policy and monetary policy, or inflation vs deflation, mostly comes down to looking at a long enough historical timeline to see the full context.
The effectiveness of monetary policy, including interest rate manipulation and asset purchases, diminishes significantly when debt is high, interest rates hit the zero bound, and the money multiplier is low. The role of monetary policy doesn't stop then, but it takes a back seat to supporting fiscal policy.