The more I read the monetarists-especially Scott Sumner-it begins clear to me that monetarism is something which does make some valuable insights but still you must be careful with as it's agenda never changes.
This is why Sumner keeps writing snarky posts about Keynesianism. The hope of monetarism is always the same-that we will be weaned from the illusions of "fiscalism." For deep problems in an economy to always being due to nominal shocks is what Sumner wants us to drink.
Therefore if we get monetary policy right there should be no problem-ever? To underscore how one sided this view is, Sumner once claimed that if Benjamin Strong had lived there would have been no Great Depression.
And this is really the difference between monetarism and Keynesianism. Monetarism is committed to laissez faire. To an extent it weakens it's own position by saying that the Federal Reserve caused the Great Depression or caused the current Great Recession. After all that's already an admission that the government should have done more. For them we can be wholly Laissez Faire if only the Fed intervenes in the proper way. Are we to believe that no depressions or recessions are at all rooted in the real economy?
It would be nice if life were this neat: just get the monetary policy right and everything else will fall into place. Unfortunately this is not the life we know. I remain of the opinion monetary policy is not irrelevant but I can't believe it's the whole ball of wax.