NEW YORK, July 22 -- The US 30-year Treasury yield has remained above 5% for the longest consecutive stretch since 2007, a milestone that has alarmed bond investors and raised questions about whether the Federal Reserve can cut interest rates before the end of the year, as persistently elevated oil prices driven by the US military campaign against Iran continue to sustain inflation well above the central bank's 2% target.

The prolonged run above 5% reflects a structural impasse rather than a cyclical one. The Federal Reserve has held its benchmark rate at 4.25%-4.50% since January, and its June meeting produced no signal of an imminent cut, as Brent crude's persistence above $90 per barrel since early June continues to reappear in headli...