The second way in which expectations can affect current real long-term interest rates involves the effect of policy on inflation expectations. In order for this effect to work, policymakers must first convince the public that policymakers will maintain a given path for the short-term nominal policy rate; thus the second effect builds upon and reinforces the first effect.
The second effect, by convincing the public that inflation will be higher in the future, converts the perceived commitment to a given path for the short-term nominal policy rate to a decline in future expected short-term real interest rates and hence in current expected longer-term real interest rates.