“He is a diplomat”
Kirby is not a diplomat. He is the WH (NSC) spokesman for national security matters. Before that, he was a Navy Pubic Affairs Officer. Which means that is and has long been just a flack, a p.r. man.
He is not a State Department diplomat by the strictest definition, that is true. When a person the upper levels of a Presidential administration represents US policy to foreign nations, that person is acting as a diplomat by definition. Their official title does not change the function or role played.
The bottom line is, for nearly two months, no nation has stopped Israel from going flat out to destroy Hamas.