Kevin Warsh went to Jackson Hole determined not to give markets forward guidance. He may have given them something more consequential instead. By insisting that underlying inflation must move clearly and sufficiently towards 2%, and that otherwise the Federal Reserve still has work to do, Warsh has transformed the September meeting from another data-dependent decision into a test of his own credibility. Markets understood the message. The probability of a September rate increase jumped from roughly 35% before his speech to more than 50%.  The problem is that investors are not entirely convinced Warsh will follow through. That matters. Since taking office, his communication has repeatedly moved markets in opposite directions. In June, he reassured investors about his commitment to 2% inflation. In July, his failure to explain why the Fed was holding rates despite persistent price pressures pushed long-term yields higher. Jackson Hole was supposed to restore clarity. It did. Perhaps too much.

Warsh has now established a relatively simple test. Inflation must demonstrate convincing progress towards the target. If it does not, policy needs to become tighter. The August CPI report, due only days before the 15–16 September meeting, therefore becomes unusually important. A benign number gives the Fed room to wait. A disappointing one leaves Warsh with a much more difficult choice. Raise rates, and he risks tightening into an economy already showing softer employment and consumption data. Do nothing and markets may conclude that his inflation rhetoric has no operational consequence. That second outcome could ultimately be more damaging. The Fed does not need to raise rates every time inflation exceeds 2%. But once its chairman publicly raises the threshold for inaction, refusing to respond when that threshold is crossed weakens the value of future communication.

Bond investors understand this. Several remain underweight long-duration Treasuries despite Jackson Hole, as they want action, not words. The concern is straightforward: if inflation remains elevated and Warsh votes to hold again, credibility could deteriorate, and long-term yields could rise rather than fall. This creates an unusual paradox. A rate increase could actually help the long end of the Treasury market. Normally, tighter monetary policy pushes yields higher. But if a September hike convinces investors that the Fed will defend its 2% target, inflation expectations and the term premium could fall, flattening the curve and potentially lowering long-term borrowing costs. That matters because Washington desperately wants lower long yields. And this is where monetary policy becomes political.

Donald Trump has consistently argued for cheaper borrowing. The Treasury, under Scott Bessent, has already intervened more aggressively in the bond market to contain long-term yields. Warsh may therefore find himself in the strange position of having to raise the Fed’s policy rate in order to convince markets that long-term rates can eventually fall. The White House may not appreciate the first part. The bond market may demand it. That is the September dilemma. There is also a deeper contradiction in Warsh’s communication strategy. He dislikes forward guidance because he believes markets should interpret the economy themselves rather than trade around promises from the Fed. That principle is defensible. But central-bank communication cannot disappear completely. Markets still need to understand the reaction function.

Jackson Hole finally provided one. Inflation moving convincingly towards 2% means patience. Inflation failing to do so means tightening. Once that framework has been stated, Warsh cannot easily ignore it. This is why the September meeting matters more than the 25 basis points themselves. The Fed’s credibility has already been questioned because markets are uncertain how much political pressure, weaker growth and inflation persistence each matter in the new regime. Warsh has now simplified the debate. He has said price stability comes first. Markets will shortly discover how literally they should take him. If August inflation is benign, Warsh escapes the confrontation. If it is not, there will be nowhere left to hide behind communication reform, reduced forward guidance or data dependence. He will have to choose. Between growth and inflation. Between Trump and the bond market. And, ultimately, between keeping rates unchanged and proving that his own words mean something.