Here's what I said in response to a commenter:
This is a long-run proposition. I know it's confusing. Tighter monetary policy, in the short run, raises nominal interest rates. Ultimately, the lower monetary growth as the result of tightening leads to lower inflation and lower nominal interest rates over a longer horizon. Look at what happened after the Volcker tightening. Nominal interest rates went up, then they came back down again as the inflation rate fell. In the short run, there is a "liquidity effect" whereby tight monetary policy tends to increase the nominal interest rate. In the long run, what dominates is the "Fisher effect" whereby an inflation premium gets built into the nominal interest rate.That's pretty much what Krugman and DeLong seem to be trying to say. What's all the heat about?