European central bankers left the Kansas City Fed’s Jackson Hole Economic Symposium unconvinced that established norms of global cooperation with the United States remain secure. Federal Reserve policymakers sought to reassure them that commitments would be honored, but more than half a dozen officials said the Fed could not guarantee protection from abrupt policy changes by President Donald Trump. European officials were particularly angered that the United States did not provide a customary warning that euros would be sold during an August 1 intervention to support the Japanese yen. They also questioned Treasury Secretary Scott Bessent’s plan to expand buybacks of longer-dated U.S. bonds, fearing that unusual efforts to restrain borrowing costs could precede further intervention. Some officials worried that political interference might eventually affect the Fed’s dollar swap lines (emergency dollar-liquidity arrangements), although the sources said there was no indication the backstops were at risk and expected them to remain unchanged. The Fed and Treasury said the measures were intended to support market stability and liquidity, not conduct monetary policy or cap interest rates. Bessent is expected to discuss financial stability with G20 finance ministers and central bank governors in Asheville, North Carolina, while Fed Chairman Kevin Warsh continued efforts to maintain relations with European officials and posed for a customary photograph with Bank of Canada Governor Tiff Macklem.