The Federal Reserve was already trapped between inflation, oil shocks and a slowing economy. It now faces something more corrosive: political occupation by procedural means. The decision by US attorney Jeanine Pirro to drop the criminal investigation into the Fed may appear, at first glance, to clear the path for Donald Trump’s preferred candidate, Kevin Warsh, to take over the central bank. But in reality, it opens a more ambiguous and potentially more dangerous chapter. Jerome Powell may lose the chairmanship in May, but his seat on the Board of Governors runs until 2028. If he stays, Trump gets his new chairman, but not full control of the institution. That matters. The Fed is not a ministry. It does not function by presidential instruction, at least not in theory. Monetary policy is decided by the FOMC, not by one man. Warsh, even as chairman, would have one vote. Powell, if he remains as governor, would still have influence, credibility and allies inside the institution. The result could be a divided Fed: one centre of formal power around Warsh, one centre of institutional memory around Powell.

For markets, this is toxic. Central banking relies on clarity. Investors need to know not only where rates are going, but who is truly shaping the reaction function. If the Fed begins to look like a battlefield between Trump’s political demand for lower rates and Powell’s more cautious inflation-focused legacy, the signal becomes blurred. And blurred signals are expensive. The timing could hardly be worse. Inflation has been above the Fed’s 2% target for more than five years. The Iran conflict has pushed oil and petrol prices higher. The US consumer is already absorbing the shock at the pump. In normal circumstances, this would argue for patience, perhaps even a more hawkish bias. Yet Trump wants lower rates, faster. He has made no mystery of it. That is the core contradiction. The economy is giving the Fed reasons to stay restrictive. The White House is giving it orders to ease.

Warsh has spoken of a new monetary policy paradigm, but has not yet defined it clearly. That may please politicians who want a break with Powell. It may worry markets that prefer boring central bankers to revolutionary ones. A Fed that suddenly appears more sensitive to presidential pressure could lower short-term rates, but it might also raise long-term yields if investors start demanding compensation for weaker inflation discipline. That is the irony. A politicised Fed may not deliver cheaper money. It may deliver a steeper curve, weaker credibility and a higher risk premium on US assets.

So the real issue is not merely whether Powell leaves or stays. It is whether the Fed remains a central bank or becomes another arena of Trumpian pressure politics. If Powell stays, the institution may become internally conflicted. If he leaves under pressure, his independence may look damaged. Either way, the market will not see a clean transition. For US interest-rate policy, the consequence is clear: uncertainty rises. Rate cuts may become politically expected, but economically harder to justify. The front end of the curve may price a more dovish chairman. The long end may price fiscal excess, inflation risk and institutional erosion. This is how credibility is lost: not in one dramatic collapse, but through a sequence of small institutional humiliations. And once the Fed’s independence becomes a question, every rate decision becomes political. That is precisely what a central bank is designed to avoid.