"Answering questions by CNN’s Wolf Blitzer before an audience at the Aspen Security Forum, Mattis said he found it inexplicable that the plot was dealt with as a law enforcement matter with no clear diplomatic or military response."
"Iran was under Mattis’ purview at Central Command. Asked afterward whether he presented military options to the White House that were rejected, he said his advice would remain confidential."
Here is the entire Aspen Security Forum interview with Gen. James N. Mattis (Ret.):