This is not good for US borrowing costs, nor ultimately for YOUR borrowing costs. But - much like the spike in gasoline prices - this was a completely foreseeable impact of what the Trump admin did in Iran. https://www.ft.com/content/1c4189e9-36af-4779-b862-d868cf2aff76?syn-25a6b1a6=1
Foreign central banks sell US Treasuries in wake of Iran war

International official holdings at New York Federal Reserve fall to lowest level since 2012

Financial Times